Qu’est-ce que le streaming HLS et quand l’utiliser ? [2025 Update]

With the decline of Adobe Flash Player, HLS (HTTP Live Streaming) has emerged as the current gold standard for delivering high-quality video and audio streams over the internet. While Low-Latency HLS (LL-HLS) and other emerging streaming formats are gaining traction for ultra-responsive live experiences, HLS remains the most widely supported and reliable protocol across devices and platforms. Dacast, a leading OVP, has built its entire delivery workflow around HLS to ensure maximum reach and performance for broadcasters and content producers.

This shift is good news for both broadcasters and viewers. HTML5 and HLS are open specifications, making them accessible and modifiable by developers, while also providing safer, more reliable, and faster streaming than earlier technologies. For content producers today, these technologies offer distinct advantages. Whether you’re live broadcasting, streaming events, or delivering video content from your website, ensuring proper playback across all platforms in the best quality is vital.

In this article, we’ll cover the role of HTML5 video streaming with HLS, including the different streaming protocols. By the end, you’ll understand the importance and benefits of HLS streaming and how it can help you deliver your best content yet.

Table of Contents

• What Is HLS Streaming, and How Does it Work?
• Recent Advances in Video Streaming
• How HLS Works (Step-by-Step)
• Modern Codec Comparison in HLS Workflows
• Securing Your HLS Streams
• Key Benefits of HLS Streaming
• Comparing HLS Streaming to Other Video Streaming Protocols
• Optimizing HLS Streaming with Dacast
• When & Where to Use HLS
• Latency Benchmarks: HLS vs. LL-HLS vs. WebRTC vs. SRT
• Low-Latency HLS (LL-HLS) Deployment Guide
• Dacast’s RTMP-to-HLS Workflow
• HTML5 HLS Streaming in the Dacast Platform
• Real-World Dacast Case Studies: Sports, Education, and Enterprise
• Future Trends in HLS Streaming
• FAQs
• Conclusion

What Is HLS Streaming, and How Does it Work?

HLS, or HTTP Live Streaming, is a live streaming protocol considered the “technology of now” for delivering video and audio over the internet. Apple introduced HLS in the summer of 2009 alongside the iPhone 3, addressing issues with accessing streaming content. Early smartphones struggled with video streaming due to QuickTime’s RTSP protocol being blocked by firewalls and slow internet speeds. HLS was developed as a firewall-friendly, efficient solution and has since become one of the most widely used streaming protocols.

Recent Advances in Video Streaming

AI’s Role in Video Streaming

Artificial Intelligence (AI) is changing how we stream video by making the process smarter and more efficient. In HLS streaming, AI helps optimize how videos are encoded by analyzing the complexity of each frame. This makes it easier to adjust settings like bitrate and buffer sizes to maintain high quality without using too much bandwidth. Whether you are dealing with an HLS streaming server or an HLS live streaming setup, AI ensures smoother delivery with less lag.

Optimizing HLS Output with AI

Using AI in HLS mode means smarter decisions when encoding video. By predicting how complex each scene is, AI can adjust the bitrate in real-time. This improves the HLS stream format by balancing quality and bandwidth usage. It also helps with HLS video stream delivery, reducing buffering and improving the viewer experience on any HLS player or HLS player online.

Reducing Bandwidth with Smarter Encoding

One of the biggest challenges in HLS technology is bandwidth usage. AI can help lower this by optimizing the HLS file format and adjusting how data is sent. Whether it is an HLS audio stream or an HLS video stream, this smarter encoding cuts down on costs while keeping the quality high.

Enhancing Viewer Experience

AI makes HLS adaptive streaming better by ensuring videos run smoothly, even when network conditions change. By tweaking the HLS media file in real-time, viewers get a better experience without constant buffering. This works whether you are using an HLS streamer for HLS broadcast or for live events or watching a recorded video.

Future of HLS with AI

As we look to the future, AI will continue to improve HLS format video delivery. From better HLS browser support to smarter security measures, businesses and broadcasters can rely on AI to make streaming more efficient. Whether you are exploring what HLS means or diving into HLS file integration, AI will play a crucial role in how we stream video in 2025 and beyond.

AI-powered HLS Encoding for Bandwidth Optimization

Adaptive Bitrate Streaming (ABR) has come a long way with the integration of AI-powered predictive analytics. This technology helps forecast network conditions, allowing for real-time adjustments to video resolution and bitrate. As a result, viewers enjoy a smooth experience even when bandwidth fluctuates.

These advancements solve a common issue in HLS streaming by reducing buffering and maintaining consistent video quality. Whether accessing an HLS URL through an HLS player online or using an HLS streaming server for live broadcasts, these improvements enhance overall performance. This evolution makes the HLS stream format more reliable and ensures better HLS quality for video streaming in 2025.

Emergence of Enhanced RTMP (E-RTMP)

While HLS remains a dominant stream format default for video delivery, Enhanced RTMP (E-RTMP) is gaining attention as a modernized version of the traditional RTMP protocol. It supports advanced audio and video codecs, multitrack capabilities, and offers better connection resilience, which is crucial for consistent HLS delivery. E-RTMP is designed to maintain backward compatibility while addressing the evolving needs of live streaming in 2025.

For broadcasters exploring what is an HLS streamer and how to stream HLS effectively, E-RTMP provides another option for low-latency streaming. It complements HLS technology by offering flexibility in stream format MPEG or HLS and enhancing overall performance in live streaming scenarios.

Adoption of Versatile Video Coding (VVC)

Versatile Video Coding (VVC) is the latest video compression standard, offering around 50% better efficiency than its predecessor, HEVC. With support for resolutions up to 16K and 360° videos, VVC is ideal for modern streaming needs. As HLS technology continues to evolve, incorporating VVC could improve HLS delivery by reducing bandwidth demands while maintaining high quality. This makes it a promising option for broadcasters using HLS files or anyone exploring how to stream HLS with minimal latency.

How HLS Works (Step-by-Step)

We’ve covered the matter-of-fact definition of HLS, but before we move on to an equally technical overview of how this protocol works, we’re going to go back to the basics. As we’ve mentioned, HLS is an important protocol for live streaming. 

The live streaming process, compatible with the greatest number of devices and browsers, looks a little bit like this:

• Capturing devices (cameras, microphones, etc.) capture the content.
• The content is sent to a live video encoder from the capturing device. 
• The encoder transmits the content to the video hosting platform via HTTP.
• The video hosting platform uses HLS ingest to transmit the content to an HTML5 video player.

This process requires two main software solutions: a live video HLS encoder and a powerful video hosting platform. 

If you choose to stream with HLS, you’ll want to ensure that both software offers the protocols and features we mentioned. HTML5 video players powered by HLS are great for reaching the largest audience since this duo is practically universal. Dacast is a feature-rich live video streaming solution that includes HLS streaming and a customizable, white-label HTML5 video player. 

HLS (HTTP Live Streaming) operates on the same HTTP protocol as regular web traffic, making it easy to deploy content through standard web servers and content delivery networks (CDNs). This protocol is designed to offer reliability across different network conditions by dynamically adjusting playback speed to optimize for both wired and wireless connections.

So, how does HLS streaming technology work in detail?

First, the HLS protocol breaks down MP4 video content into short segments, typically around 10 seconds each, using the .ts (MPEG2 Transport Stream) format. These video segments are then stored on an HTTP server, which delivers them to viewers on their devices via HTTP.

HLS supports video encoded in either the H.264 or HEVC/H.265 codecs, making it versatile for various devices and networks. 

As part of the streaming process, the server generates an M3U8 playlist file (also known as a manifest file) that indexes the video chunks. This playlist file is crucial because it remains accessible even if you choose to stream with only a single quality level.

When streaming, HLS technology ensures smooth playback by allowing a video player, such as an HTML5 player, to detect any changes in network quality. If the network quality fluctuates, the player first reads the main M3U8 playlist file and selects the appropriate video quality for optimal playback. It then accesses a quality-specific index to retrieve the video chunk that aligns with the viewer’s current position in the video.

For instance, streaming services like Dacast offer an M3U8 online player to test HLS streams, making it easier for users to ensure their HLS streaming setup functions as intended. While this might sound technically complex, HLS streaming runs seamlessly in the background, creating an uninterrupted viewing experience for the end user.

Modern Codec Comparison in HLS Workflows

While HLS can work with multiple codecs, the choice of codec can greatly impact streaming efficiency, latency, and device compatibility. The table below compares the most relevant modern codecs for HLS workflows.

HLS streaming codec comparison AV1 vs HEVC vs H.264 vs VVC

Securing Your HLS Streams

Ensuring secure video content distribution is essential, especially if your business relies on live streaming for revenue. Using M3U8 links with HLS provides not only secure delivery but also broad compatibility with HTML5 players and mobile applications.

In HLS streaming, the M3U8 playlist file organizes and sequences multimedia segments for playback. The HTML5 player uses this file to locate and play segments efficiently. Importantly, the M3U8 file also enables security features, such as tokens that authenticate viewers with your streaming servers. These tokens enforce measures like password protection, geo-restrictions, or subscription-based access, ensuring that only authorized viewers can access your content.

This secure framework supports one type of monetization: access-based monetization. By controlling who can view your content—through subscriptions, pay-per-view, or region-specific restrictions—you protect your video assets while generating revenue from legitimate viewers.

In addition, HLS supports advertising-based monetization, which operates independently of viewer access controls:

• Server-Side Ad Insertion (SSAI): Ads are stitched directly into the HLS stream on the server, ensuring smooth playback without being blocked by ad blockers. SSAI allows precise targeting and reporting while maintaining secure content delivery.
• Interactive Ad Formats: HLS can deliver clickable overlays, hotspots, or other interactive ad experiences alongside the stream, boosting engagement and creating additional revenue opportunities.

By combining secure access control with ad-based video monetization options, broadcasters and content providers can both protect their assets and maximize revenue within a single, reliable HLS streaming workflow.

Accessibility in HLS

HLS streaming supports a range of features that make content accessible to all viewers, ensuring compliance with accessibility standards and expanding audience reach.

1. Multi-Language Audio Tracks

HLS allows multiple audio tracks within a single stream, enabling viewers to switch between different languages seamlessly.

Each track is referenced in the M3U8 playlist, and HTML5 players can provide language selection controls, catering to international audiences or multilingual regions.

2. Sign Language Support (Video-in-Video)

HLS can deliver picture-in-picture or video-in-video streams, allowing sign language interpreters to appear alongside the main content.

This can be implemented using additional video tracks or synchronized secondary streams, ensuring that deaf or hard-of-hearing viewers receive the same information as hearing audiences.

3. Closed Captions & Subtitles

HLS supports WebVTT, CEA-608/708, or TTML caption formats for both live and on-demand streams.

Captions can be embedded in the stream or provided as external subtitle files, and players allow toggling captions on/off.

Compliance with regulations like ADA, FCC, or EU accessibility directives ensures legally and socially responsible content distribution.

Benefits:

• Expands audience reach to international, deaf, and hard-of-hearing viewers.
• Enhances user experience and engagement.
• Supports compliance with legal and industry accessibility standards.

HLS for Hybrid Events

HLS powers hybrid events like corporate town halls and conferences, delivering secure, high-quality streams across devices. Low-Latency HLS enables near real-time interactivity with live Q&A, polls, and chat. Multi-bitrate streaming ensures smooth playback, while token authentication protects content. HLS combines scalability, engagement, and reliability, creating a seamless experience for both in-person and remote participants.

Security Features: How to Secure HLS Streams with DRM and Token Authentication

Dacast ensures your content remains protected and accessible only to authorized users through a combination of advanced security technologies:

Token Authentication

• Every playback request is validated using secure, time-limited tokens.
• Prevents unauthorized access by ensuring only legitimate users or devices can stream content.
• Supports integration with Single Sign-On (SSO) and custom authentication systems for enterprise use.

Digital Rights Management (DRM)

• Supports major DRM standards such as Widevine, FairPlay, and PlayReady.
• Controls how content can be used, including restrictions on downloading, screen recording, or offline playback.
• Enables tiered content access (e.g., subscriptions, pay-per-view, or enterprise licensing).

Encryption

• At-rest encryption protects media files on servers using AES-256 standards.
• In-transit encryption via HTTPS and HLS/LL-HLS ensures streams cannot be intercepted or tampered with.
• End-to-end encryption options available for high-value or sensitive content.

Geo-Restrictions

• Limit content access based on user location.
• Prevents unauthorized viewing from regions where distribution rights are restricted.
• Flexible configuration allows both whitelist and blacklist approaches for granular control.

Additional Protections

• IP whitelisting/blacklisting to secure enterprise streams.
• Multi-factor authentication (MFA) for content managers and admins.
• Detailed logging and audit trails for compliance and monitoring.

Security Case Studies: Tokenization + DRM

Sports Broadcaster — Tokenization at Scale
A European sports league saw match links shared online within minutes. By adding short-lived, user-specific URL tokens to HLS playlists, shared links expired almost instantly. Pirated streams dropped by over 80%, and legitimate logins rose.

Entertainment Network — DRM Protection
A global OTT service faced high-quality screen captures of new releases. Switching to multi-DRM (Widevine, FairPlay, PlayReady) encrypted streams and enforced device limits, playback rules, and capture blocking. High-quality piracy fell by over 90%.

Bottom Line:
Tokenization stops casual sharing, while DRM thwarts advanced piracy. Combined, they safeguard HLS streams and protect revenue.

Key Benefits of HLS Streaming

Many vital benefits come with utilizing HLS streaming, including:

Wide Compatibility 

A key benefit of this protocol is its compatibility features. Unlike other streaming formats, HLS is compatible with many devices, operating systems, browsers, and firewalls. It supports playback across most network infrastructures and ensures smartphones automatically select the appropriate data rate when playing media. This means fewer complications at the user’s end and a seamless viewing experience.

However, latency (or lag time) tends to be in the 15–30 second range with HLS live streams. It would be best if you used other tools to get quick HLS streaming.

That’s certainly an essential factor to keep in mind. Dacast now offers an HLS direct low-latency streaming feature, which works with any HLS-compatible encoder. With our  low-latency streaming option, you can overcome the long latency associated with HLS streaming.

Encoding at Multiple Quality Settings

Versatility makes HLS video streaming stand out from the pack. On the server side, content creators often have the option to encode the same live stream at multiple quality settings. In turn, viewers can dynamically request the best option available, given their specific bandwidth at any given moment. In other words, the data quality can differ from chunk to chunk to fit different streaming device capabilities.

That’s known as multi-bitrate streaming and is a tool that helps enhance one’s viewing experience and results in happier viewers of your content.

That’s best explained with an example. Let’s say, in one moment, you’re sending a full high-definition video. Moments later, a mobile user encounters a “dead zone” in which their quality of service declines. With HLS streaming, this is not an issue. The player will detect this decline in bandwidth and instead deliver lower-quality movie chunks at this time. HLS streaming allows you to provide the best viewing experience to your viewers.

HLS also supports closed captions embedded in the video stream, and even synchronized playback of multiple streams, which is especially useful in multi-camera productions or events.

To learn more about the technical aspects of HLS, we recommend the extensive documentation and best practices provided by Apple.

Scalability

HLS is highly scalable for delivering live streams and video content across global content delivery networks (CDNs) using ordinary web servers. CDNs share the workload across a network of servers to accommodate a spike in viewership and larger-than-expected live audiences.

CDNs also cache video and audio segments to help deliver a high-quality video streaming experience and improve the viewer experience.

Other benefits of HLS streaming include:

• Ad insertion through the VPAID and VAST interfaces
• Cross-device compatibility
• Piracy protection with extensive support for Digital Rights Management (DRM) technologies
• Strong advertising standards support
• Better overall security, making it harder for unauthorized access or redistribution

Comparing HLS Streaming to Other Video Streaming Protocols

Over the years, tech companies have introduced several new streaming solutions into the market through media streaming protocols. Generally, each of these solutions aims to expand video streaming possibilities. 

However, industry conflicts can arise similar to the HD-DVD vs. Blu-Ray format wars or the even older Betamax vs. VHS showdown. HLS is currently the best option for streaming media protocols, but it wasn’t always that way, nor will it remain so forever. Let’s review several current streaming protocols to better understand the innovations of HLS streaming protocol offers today.

Optimizing HLS Streaming with Dacast

To help you enhance your HLS streaming setup, here’s a practical checklist covering key strategies for improving quality, security, and latency.

Quality

• Use a high-quality HLS encoder.
• Implement adaptive bitrate streaming for multiple resolutions.
• Test streams on various devices and network conditions.
• Use HTML5 HLS players for seamless cross-browser playback.
• Ensure consistent keyframe alignment across renditions.

Security

• Enable DRM (Digital Rights Management) protection.
• Use token-based authentication for HLS links.
• Encrypt HLS segments (AES-128 or SAMPLE-AES).
• Serve all streams over HTTPS.
• Restrict playback to authorized domains or apps.

Latency

• Consider Low-Latency HLS (LL-HLS) for reduced buffering.
• Reduce segment size (e.g., 2–4 seconds) for faster delivery.
• Apply CMAF packaging for lower startup delay.
• Use predictive buffering to improve responsiveness.
• Monitor end-to-end latency and adjust CDN configuration as needed.

By incorporating these strategies, both technical and non-technical readers can improve their HLS streaming setup to ensure better quality, security, and minimal delay in 2025 and beyond.

HLS Streaming for Sports and Live Events in 2025

HLS streaming has become the go-to solution for broadcasters looking to deliver high-quality live streams to a global audience. Using an HLS feed, broadcasters can send real-time video to viewers across various devices, from smartphones to smart TVs. One key benefit is its ability to adjust the video quality dynamically based on the viewer’s internet speed, ensuring smooth playback with minimal buffering. This is particularly useful for sports broadcasts or live concerts, where a steady stream is crucial for maintaining engagement. With an HLS server, broadcasters can manage multiple streams efficiently, ensuring their content reaches audiences without interruption.

Cloud-Based Multi-CDN Strategies for HLS

For broadcasters delivering HLS streams to viewers worldwide, relying on a single Content Delivery Network (CDN) can be risky. Performance can vary drastically by region, and during peak traffic or outages, a single CDN may fail to keep up. A cloud-based multi-CDN strategy addresses this by dynamically routing traffic across multiple CDN providers, ensuring faster, more reliable delivery for global audiences.

1. Why Multi-CDN Matters for HLS

No single CDN performs equally well everywhere. One provider might have lightning-fast delivery in North America but slower response times in Southeast Asia or parts of Africa. Multi-CDN setups let you connect each viewer to the best-performing network for their location and device, reducing buffering, improving stream start times, and delivering a consistent viewing experience.

2. How Cloud-Based Orchestration Works

Modern multi-CDN orchestration platforms operate in the cloud and rely on real-time performance monitoring. They track latency, throughput, and error rates for each CDN in different regions. Using DNS-based traffic steering or application-level routing, these systems automatically direct each HLS playlist and segment request to the optimal CDN at that moment. This dynamic switching is seamless for the viewer.

3. Benefits for Global Readability

HLS relies on synchronized, accessible segments for smooth playback. A multi-CDN strategy provides redundancy—if one CDN fails to deliver a segment, another can step in immediately. This prevents segment mismatches and maintains adaptive bitrate switching, so viewers experience stable playback regardless of location.

4. Best Practices

• Select CDNs with strong HLS performance in your target markets.
• Use automated monitoring and failover to prevent downtime.
• Ensure your origin server can handle sudden shifts in traffic load.

By leveraging a cloud-based multi-CDN strategy, broadcasters can overcome regional performance gaps, reduce streaming interruptions, and maintain a consistently readable, high-quality HLS experience for viewers anywhere in the world.

Content Creation and Distribution

For content creators and businesses producing on-demand video content, HLS streaming offers a reliable way to distribute their videos. By using an HLS player online, creators can embed video on their websites or apps, allowing for easy access to their audience. The HLS file format supports adaptive bitrate streaming, ensuring a seamless experience for users regardless of their device or network conditions. This is especially helpful for companies offering educational videos or corporate training, where clarity and ease of access are essential. As more platforms embrace HTML5 HLS, creators can reach wider audiences with fewer technical barriers.

Devices and Browsers That Support HLS

The HLS streaming protocol is widely supported across multiple devices and browsers. Initially limited to iOS devices like iPhones, iPads, and the iPod Touch, the HLS streaming server is now supported by the following devices and browsers:

• All Google Chrome browsers
• Mozilla Firefox 
• Safari
• Opera
• Microsoft Edge
• iOS devices
• Android devices 
• Linux devices
• Samsung Internet
• Microsoft devices
• macOS platforms 

At this point, HLS is a nearly universal protocol. If you want to stream online, you want to use HLS streaming. 

When & Where to Use HLS

Currently, we recommend that broadcasters always adopt the HLS streaming protocol. It’s the most up-to-date and widely used protocol for media streaming. For example, 45% of broadcasters reported using HLS streaming in this Video Streaming Latency Report. RTMP came in second, with 33% of broadcasters using that alternative. And MPEG-DASH trailed behind even further, used by only 7% of broadcasters.

1. Streaming to Mobile Devices

When it comes to streaming to mobile devices and tablets, you need to use HLS. As of January 2025, 62,69% of all web traffic comes through mobile phones. Mobile devices now make up most of the internet traffic, so any streaming solution you use needs to work with mobile devices. HLS is essential for mobile streaming.

2. Streaming With an HTML5 Video Player

The native HTML5 video player is the standard player used to play video content on websites, apps, and mobile devices. However, HTML5 video players don’t support RTMP or HDS.  You need to use HLS with an HTML5 video player. HLS allows for content delivery to your video player. Along with reaching mobile devices, these considerations point towards HLS as the default standard. If you’re stuck using Flash technology for the moment, RTMP will be a better delivery method—but only if you have no other option.

Securing HLS video streams is essential to protect valuable content from unauthorized access. Using encryption methods helps safeguard HLS files during transmission, while token-based authentication ensures only approved viewers can access the HLS link.

Digital rights management (DRM) adds another layer of protection by controlling how HLS output is viewed or shared. These security strategies are vital for keeping HLS feed content exclusive, whether streaming HLS for live events or using an HLS player for on-demand video.

One Drawback of HLS Streaming

HLS streaming does have one disadvantage, which we mentioned above. Namely, it has a relatively higher latency than some other protocols. That means that HLS streams are not quite as “live” as the term live streaming suggests. Generally, with HLS, viewers can experience delays of up to 30 seconds (or more, in some cases). That means that if you’re streaming a video, it’ll take 30 seconds to reach the viewer, so they see the content as close to live as possible.  

That can be an issue if you are streaming something like a sporting event, where people may be commenting on the event, and you don’t want a large delay between what is happening and when your viewers see the content. 

However, this delay is manageable with many live streams, such as a conference or a graduation ceremony. That said, this isn’t a problem for most broadcasters. Most live streams can handle that delay without causing user dissatisfaction. One protocol that works well to reduce latency with HLS video streaming is Low-Latency CMAF for DASH. This protocol works with the content delivery network and HTML5 video player to carry the weight where HLS streaming is lacking. 

If you’re streaming something such as live sports, you should use this; if you don’t want a long delay, you should use this.  Using tools such as CMAF allows you to overcome one of the few drawbacks of using HLS video streaming. 

Another (minor) drawback worth noting is that HLS streaming requires at least three segments to remain in the queue before it allows video playback.

Addressing Latency Concerns

To address HLS latency concerns, Low-Latency HLS (LL-HLS) has emerged as a solution. This protocol reduces delays by segmenting video more efficiently, allowing for faster delivery of content. Additionally, leveraging AI for predictive buffering helps optimize playback, reducing interruptions and improving the overall viewer experience. 

By using these strategies, businesses and content creators can significantly enhance real-time HLS streaming, ensuring smooth playback for audiences, especially in live streaming environments where low latency is crucial.

Latency Benchmarks: HLS vs. LL-HLS vs. WebRTC vs. SRT

To put these latency solutions into perspective, it’s helpful to compare HLS and LL-HLS with other popular low-latency protocols. The table below outlines typical and best-case latency benchmarks, along with their ideal use cases.

Low-Latency HLS (LL-HLS) Best Practices

Low-Latency HLS reduces the delay between live events and viewers, making it ideal for sports, auctions, gaming, or interactive content. Optimizing LL-HLS involves careful choices in segmenting, packaging, and encoding.

1. Segment Sizes

Shorter segments reduce latency:

• Target 2–4 seconds per segment in traditional HLS. For LL-HLS, you can break it into partial segments of 200–500 ms (also called “parts” in CMAF/LL-HLS terminology).
• Smaller parts allow the player to fetch video faster, reducing end-to-end delay.

Key considerations:

• Too small → higher HTTP request overhead and potential server load.
• Too large → increases latency; partial segments can’t be smaller than your encoder GOP (Group of Pictures) structure.

Recommended practice:

• Use CMAF chunked encoding with 4–6 parts per segment.
• Align segments to keyframes for better decoder efficiency.

2. CMAF Packaging

CMAF (Common Media Application Format) is the cornerstone for LL-HLS. It allows fragmented MP4 (fMP4) segments compatible across HLS and DASH.

Best practices for LL-HLS CMAF packaging:

• Use fMP4 segments with #EXT-X-PART tags to enable partial segment delivery.

Segment alignment:

• Ensure audio and video are synchronized in each part.
• Each part should start with a keyframe to reduce buffering.

Single-bitrate vs. multi-bitrate:

• Use multi-bitrate ABR for adaptive streaming. Each bitrate must follow the same segment/part alignment.

HTTP/2 or HTTP/3:

• Helps reduce the overhead of frequent requests for small parts.

3. Encoder Configuration

The encoder is critical to achieving low-latency streams. Proper configuration reduces delay without sacrificing quality.

Best HLS encoder settings for low-latency streaming in 2025: 

GOP size:

• Small GOPs (1–2 seconds) reduce latency but increase bitrate overhead.
• LL-HLS recommends GOP = segment duration or slightly less.

Keyframes:

• Each segment/part should start with a keyframe.
• Ensures smooth playback and fast start for new viewers.

Encoding profile:

• Use main or high profile for H.264, or AV1/HEVC for modern setups.
• Low-latency streaming benefits from hardware-accelerated encoders to reduce processing delay.

Chunked output:

• Enable fragmented MP4 output (CMAF).
• Set part size = 200–500 ms to feed the HLS server efficiently.

Buffering strategy:

• Encoder-side buffers should be minimal to avoid adding delay.

Consider CBR vs. VBR trade-offs: CBR ensures more consistent delivery; VBR can save bandwidth but may introduce micro-bursts.

Additional Tips

• HTTP/2 Push (optional): Some platforms support pushing LL-HLS parts to reduce request overhead.

Player tuning:

• Enable preload hints and fast-start options for smoother playback.

Server-side considerations:

• Use a CDN that supports HTTP/2, chunked transfer, and LL-HLS, otherwise latency gains can be lost.

Low-Latency HLS (LL-HLS) Deployment Guide

Here’s a Low-Latency HLS (LL-HLS) Deployment Guide that covers optimal segment durations, encoder configurations, and a CDN readiness checklist.

Optimal Segment Durations

In LL-HLS, segment and part durations directly affect latency, playback stability, and startup times.

Pro tip: Use CMAF (Common Media Application Format) packaging to enable chunked transfer encoding and interoperability across platforms.

Encoder Settings

To ensure compatibility and consistent low-latency performance:

CDN Support Checklist

Before going live, confirm your CDN supports:

• HTTP/2 or HTTP/3 – Required for efficient parallel part delivery.
• Chunked Transfer Encoding – Enables sending parts before a segment is complete.
• Partial Segment Caching – Stores and serves .m4s parts individually.
• Preload Hints (#EXT-X-PRELOAD-HINT) – Reduces player wait time.
• TLS (HTTPS) – Ensures secure, encrypted delivery.
• CORS Headers – Needed for cross-domain playback.
• Byte-Range Requests – Supports partial object retrieval (some LL-HLS workflows).
• Consistent Global Edge Network – Reduces latency spikes in geographically dispersed audiences.
• Origin Shielding – Minimizes repeated requests to origin for the same part.
• Log Access – For monitoring and troubleshooting low-latency performance.

Common HLS Troubleshooting Tips

Even with a robust HLS setup, streaming issues can occasionally arise. Understanding common problems and how to fix them ensures a smooth viewing experience for your audience.

1. Playlist Errors

Playlist issues are among the most frequent HLS problems. If your M3U8 playlist fails to load or throws errors, first check the file for syntax mistakes. Ensure all segment URLs are correct, accessible, and properly referenced. Also, confirm that your playlist’s target duration matches the segment lengths—mismatched durations can cause playback errors or buffering.

2. Segment Mismatches

Segment mismatches occur when video segments referenced in the playlist do not exist or differ from the expected encoding parameters. Verify that all segments are properly generated by your encoder and that segment naming conventions match those in the playlist. Additionally, ensure segment lengths are consistent across bitrates to prevent adaptive bitrate switching issues.

3. HTTPS and Certificate Issues

Secure streaming over HTTPS is essential for modern web and mobile players. If your HLS stream fails to load, check that your SSL/TLS certificate is valid, not expired, and correctly installed on your server. Mixed content errors—where your webpage is HTTPS but your stream is HTTP—can also prevent playback. Always serve your HLS playlist and segments over the same secure protocol as your site.

4. Player Compatibility

Different HTML5 and mobile players may handle HLS differently. If a stream works in one player but not another, check for codec support, encryption compatibility, and segment duration requirements. Testing across multiple devices ensures broader reliability.

5. Logging and Monitoring

Finally, enable server logs and monitor CDN performance. Tools like browser developer consoles and HLS analyzers can pinpoint errors quickly, helping you address issues proactively before they affect viewers.

By systematically checking playlists, segments, security, and player compatibility, you can minimize HLS streaming disruptions and maintain a seamless experience.

Dacast’s RTMP-to-HLS Workflow

We’ve covered what HLS is, how it works, and when to use it. We’ve also looked at alternative streaming protocols from the past and present. Now, let’s discuss how to build an RTMP Ingest to HLS workflow. If you’re using a streaming service like Dacast, you need to build a workflow that begins as RTMP. This is much simpler than it sounds. 

You must configure your hardware or software encoder to deliver an RTMP stream to the Dacast servers. Most encoders default to RTMP, and quite a few only support that standard. For Dacast users, our CDN partners then ingest the RTMP stream and automatically rebroadcast it via both HLS and RTMP. From there, viewers default to the best-supported method on their own devices. 

Using HLS is relatively straightforward with a professional, full-service OVP. On Dacast, all live streams default to HLS delivery. On computers that support Flash, we fall back on RTMP/Flash to reduce latency. However, HLS is supported automatically on every Dacast live stream and is used on almost all devices. As we discussed above, HLS streaming is delivered through an M3U8 file. An M3U8 file is a playlist containing references to media files’ location for playback. Unlike its predecessor, M3U, which may use various character encodings, M3U8 exclusively uses UTF-8, enhancing its compatibility and reliability across different streaming platforms and devices. On a local machine, these would consist of file paths. For live streaming on the internet, that M3U8 file would contain a URL (the one on which your stream is being delivered). 

Another relevant process to note quickly is transmuxing. Transmuxing is the process that repackages content files without distorting the content itself. That allows the content to flow more easily between software via the RTMP and HLS protocols.

HTML5 HLS Streaming in the Dacast Platform

The HLS protocol has become the go-to approach for streaming content with HTML5 video players. If you’re not familiar with HTML5 video streaming, it’s one of the three main approaches to video streaming today. With HTML5, the content-hosting website uses native HTTP to stream the media directly to viewers. Content tags (e.g.,

These tags provide direction to the HTTP protocol (HLS) and what to do with this content. HTTP displays the text, and an audio player plays audio content. 

Like HLS, HTML5 is customizable for broadcasters and free for viewers. To learn more, you can check out our related post on optimizing HTML5 video players with HLS.  We’ve also written extensively about the transition from Flash-based video (usually delivered via RTMP) to HTML5 video (usually delivered using HLS). Check out our “Flash is Dead” RTMP-focused blog post for more on that subject, including why it’s important to use an HTML5 video player. 

If you’re streaming over Dacast, you’re already using a fully compatible HTML5 video player. Content delivered via Dacast defaults to HTML5 delivery. 

However, it’ll use Flash as a backup method if HTML5 is not supported on a given device or browser. That means that even older devices with Flash will have no problem playing your content over your Dacast account. Of course, some broadcasters may prefer to use a custom video player. Luckily, it’s quite simple to embed your HLS stream within any video player. 

For example, if you’re using JW Player, insert the M3U8 reference URL into the code for your video player. Here’s a visual example: var playerInstance = jwplayer(“myElement”); playerInstance.setup({ file: “/assets/myVideoStream.m3u8”, image: “/assets/myPoster.jpg” }); 

Another note about using HLS and an HTML5 video player with Dacast is that Dacast uses the THEOplayer. THEOplayer is a universal video player that can be embedded in websites, mobile apps, and any platform you can think of. As mentioned before, compatibility is critical when choosing video players and protocols since you want to reach the most people possible.

RTMP to HLS Streaming Workflow

Step 1: Capture Video (Camera / Source)

Input: Live camera, webcam, or other video sources.

Requirements:

• Consistent frame rate (e.g., 30 fps or 60 fps).
• Resolution suitable for your stream (1080p, 720p, or lower for bandwidth savings).
• Optional: Add overlays, graphics, or encoding effects before sending to encoder.

Step 2: Encode Video (Encoder)

Function: Converts raw camera feed into a compressed digital format suitable for streaming.

Encoder types:

• Hardware encoders (e.g., Teradek, Blackmagic, or dedicated appliances).
• Software encoders (e.g., OBS, Wirecast, FFmpeg).

Key encoder settings for RTMP → HLS:

• Video codec: H.264 (most compatible), H.265/HEVC if supported.
• Audio codec: AAC.
• Bitrate: Choose single or multiple bitrates for adaptive streaming.
• Resolution & framerate: Match camera source or downscale as needed.
• Output protocol: RTMP push to a streaming server or CDN.

Step 3: Streaming Server / CDN

Function: Receives RTMP stream and packages it into HLS for delivery.

Tasks performed:

• RTMP input is converted to HLS (.m3u8 playlists + .ts or CMAF fMP4 segments).
• Generates multi-bitrate ABR playlists for adaptive streaming.
• Handles security (token authentication, geo-restrictions, DRM).

Low-latency optimization (optional):

• Use fragmented CMAF segments for partial delivery.
• Enable HTTP/2 or HTTP/3 to reduce request overhead.

Step 4: HTML5 Player

Function: Plays HLS stream in a web browser, mobile app, or smart TV.

Player requirements:

• HLS-compatible (native iOS Safari supports HLS; for other browsers use HLS.js or Shaka Player).
• Supports adaptive bitrate playback.
• Handles security tokens or DRM licenses if implemented.

Playback behavior:

• Loads playlist (.m3u8), fetches segments, and buffers for smooth playback.
• Adapts quality based on user bandwidth.

Step 5: Viewer Experience

End-to-end latency: Typically 15–30 seconds for standard HLS, lower with LL-HLS.

Features:

• Smooth playback with adaptive bitrate switching.
• Secure access if token authentication or DRM is enabled.
• Wide compatibility across devices and browsers.

Real-World Dacast Case Studies: Sports, Education, and Enterprise

At Dacast, we empower organizations across industries to deliver high-quality, reliable, and secure live and on-demand video. Here’s how our customers are leveraging Dacast to reach their audiences.

Sports: NexGen Ultimate Frisbee Pay-Per-View Streaming

NexGen leveraged Dacast’s platform to deliver live pay-per-view streams of Ultimate Frisbee games worldwide. By utilizing Dacast’s Streaming as a Service platform, NexGen ensured high-quality broadcasts without technical issues, enhancing the viewing experience for fans across the globe.

Read the full case study here: NexGen delivers pay per view live streams of Ultimate Frisbee games.

Education: Graduation Streams Without Borders

Universities trust Dacast to broadcast large-scale events seamlessly. For example, Imperial College London streamed a virtual graduation for over 50,000 attendees worldwide, showcasing our ability to handle global-scale events.

With multi-CDN HLS delivery, we automatically route traffic through multiple CDNs to ensure smooth streaming for viewers everywhere, even during high-traffic spikes. Read our customer story: Imperial College London Graduation.

Enterprise: Floodin PRO’s B2B Video Hosting in Tourism

Floodin PRO utilized Dacast’s video hosting and editing tools to transform the tourism industry. By integrating Dacast’s platform, Floodin PRO reduced operating costs, increased revenue streams, and boosted profits for users, showcasing the platform’s versatility in enterprise applications.

Explore the case study here: Floodin PRO Case Study: Using Dacast for B2B Video Hosting in Tourism.

The Future of Live Streaming

Before wrapping things up, let’s recap our discussion of some of the advantages of the HLS streaming protocol. First, there’s no particular infrastructure required to deliver HLS content. Any standard web server or CDN will function well. 

Additionally, firewalls are much less likely to block content using HLS. In terms of technical functionality, HLS will play video encoded with the H.264 or HEVC/H.265 codecs. It then chops the video into 10-second segments. Remember, latency for delivery tends to be in the 30-second range.  However, Dacast now has a low-latency HLS live streaming solution that reduces latency to 10 seconds or less. The HLS protocol also includes several other built-in features. For example, HLS is a protocol. That means the client device and server dynamically detect the user’s internet speed and then adjust video quality in response.

Other beneficial HLS features include support for embedded closed captions, synchronized playback of multiple streams, advertising standards (i.e., VPAID and VAST), DRM, and more. 

While HLS is the current gold standard for live streaming, it won’t stay that way indefinitely. We expect MPEG-DASH to become increasingly popular in the coming years.  As that shift takes place, we’ll see other changes, such as the transition away from h.264 encoding to h.265/HEVC. This new compression standard provides much smaller file sizes, making 4K live-streaming a real possibility. However, that time isn’t here yet. 

For now, it’s vital to stick with the established standards to reach as many users as possible on their devices. In other words, HLS is the streaming protocol of the present.

Future Trends in HLS Streaming

Video streaming is changing fast, and HLS is evolving with it. From smarter AI-driven optimization to immersive AR and VR, smarter multi-CDN delivery, and greener, more efficient workflows, these trends are shaping how we’ll watch and experience video in the near future.

AI-Driven Streaming Optimization

AI and machine learning are transforming adaptive streaming. Predictive algorithms can analyze real-time network conditions, anticipate bandwidth drops, and adjust bitrates on-the-fly. This reduces buffering and startup delays, while optimizing video quality per device, ensuring a seamless experience across millions of concurrent viewers.

Predictive Bitrate Ladders:

AI can generate optimized bitrate ladders tailored to your specific content and audience. Instead of relying on static bitrate tiers, predictive models analyze historical viewership patterns, device capabilities, and network conditions to automatically select the most efficient set of bitrates. This maximizes visual quality while minimizing bandwidth usage and avoiding unnecessary network congestion.

Automated Quality Monitoring:

Machine learning tools continuously monitor stream quality in real-time, detecting anomalies such as frame drops, stuttering, or audio-video desync. Automated alerts allow broadcasters to quickly respond to quality issues, ensuring consistent viewer experience without manual intervention.

AI-Driven Error Detection:

Beyond monitoring, AI systems can predict and prevent potential errors before they impact viewers. This includes detecting potential encoding failures, CDN delivery issues, or playback interruptions, and triggering corrective actions automatically. The result is faster problem resolution, higher uptime, and smoother streaming experiences.

Combined, these AI-driven optimizations enable broadcasters to deliver high-quality, low-latency streams at scale, reducing operational overhead while providing a premium viewing experience.

Immersive AR/VR Streaming

HLS is evolving to support high-resolution 360° video and interactive VR content. By leveraging chunked segment delivery and adaptive bitrate techniques, broadcasters can stream fully immersive AR/VR experiences with minimal latency, enabling real-time interactivity without compromising visual fidelity.

Beyond VR, HLS can also power interactive formats such as shoppable videos, live quizzes, and real-time polls. These features turn passive viewing into an engaging, two-way experience, driving higher audience retention and boosting monetization opportunities.

Accessibility-First Delivery

Accessibility is becoming a non-negotiable part of streaming. HLS now supports closed captions, multiple audio tracks for different languages or descriptive audio, and compliance with WCAG (Web Content Accessibility Guidelines) for video. This ensures that streams are inclusive, meeting both audience expectations and legal requirements in multiple regions.

Multi-CDN Scaling and Orchestration

Delivering global HLS streams reliably requires orchestrating multiple CDNs. Advanced routing and dynamic failover ensure consistent low-latency delivery, mitigate congestion, and maintain quality-of-experience even under sudden traffic spikes or regional outages, providing uninterrupted streaming at massive scale.

Sustainable, Efficient Streaming

Next-generation streaming workflows leverage edge computing to deliver faster, more efficient HLS streams. By processing video closer to viewers at edge servers, latency is reduced, startup times improve, and adaptive bitrate decisions can be made in real-time. Regional caching ensures that popular content is delivered locally, minimizing backbone traffic and enhancing quality for audiences around the world.

When combined with advanced codecs like AV1 and VVC and powered by green data centers, edge computing enables higher-resolution streaming while lowering bandwidth consumption and energy usage. This approach not only maximizes performance but also aligns with responsible, sustainable operational practices.

Newer codecs such as VVC and AV1 can deliver the same visual quality at up to 50% less bitrate than older standards like H.264, reducing both data transfer costs and carbon footprint. This codec efficiency, paired with renewable-powered infrastructure, positions HLS as a future-proof and environmentally responsible streaming protocol.

FAQs

What is HLS streaming? (definition + LL-HLS update)

What is HLS? HTTP Live Streaming is Apple’s HLS streaming protocol that delivers video via small segments over HTTP, enabling broad device compatibility. In 2025, Low-latency HLS reduces end-to-end delays to 2–5 seconds using CMAF parts for real-time playback while maintaining smooth adaptive streaming.

How does Low-Latency HLS work? (with CMAF)

CMAF streaming splits segments into partial parts, which are delivered progressively. The player fetches these parts early, reducing latency. HLS live streaming workflow ensures continuous playback, with preload hints and adaptive bitrate adjustments so viewers experience near-real-time streaming without interruptions.

Is HLS better than MPEG-DASH/WebRTC/SRT in 2025? (pros/cons table)

What are the best encoder settings for HLS?

For HLS video, use H.264 High Profile, Level 4.1/4.2, AAC-LC stereo 128–192 kbps. GOP length matches segment duration. Enable adaptive bitrate HLS with multiple renditions. Use CMAF packaging for LL-HLS, keeping buffers stable for smooth HLS adaptive bitrate streaming.

How do I protect my HLS stream from piracy?

Secure HLS streaming requires AES encryption, HTTPS, token authentication, DRM, and watermarking. Restrict playback to approved domains or IPs. This protects the HLS media streaming protocol and ensures only authorized viewers can access content without interrupting adaptive delivery.

Can I monetize HLS streams with ads? (SSAI, VPAID, VAST)

Yes. HLS video delivery supports server-side ad insertion (SSAI) and client-side VAST/VPAID ads. Integrating ads into the HTML5 HLS player allows pre-roll, mid-roll, and post-roll monetization without affecting HLS adaptive bitrate streaming quality or viewer experience.

Does HLS support 4K, 8K, or VR streaming?

HLS streaming 2025 supports 4K, 8K, and VR content using HDR and equirectangular projections. High-resolution delivery relies on adaptive bitrate ladders and optimized CMAF segments to maintain smooth HLS video performance across devices and networks.

How do I test an HLS stream? (tools, M3U8 validators)

Streaming with M3U8 playlist files can be validated using Apple’s Media Stream Validator, FFmpeg, hls.js, or VLC. Test latency, bitrate switching, and playback stability. Ensure your HLS adaptive bitrate streaming setup works reliably in real-world conditions across networks and browsers.

What is the typical latency for HLS and LL-HLS?

Standard HLS has 15–30s latency. Low-latency HLS with CMAF parts drops this to 2–5s. Monitoring the HLS protocol ensures minimal delays while maintaining buffer stability, making live events and interactive streaming more responsive than traditional HLS video delivery.

Why choose Dacast for HLS streaming?

Dacast provides end-to-end HLS video delivery with global CDN support, LL-HLS, secure HLS streaming, monetization, analytics, and DRM. Its HTML5 HLS player compatibility simplifies deployment, offering broadcasters a reliable and scalable HLS streaming solution for live and on-demand content in 2025.

Low-latency HLS vs WebRTC for interactive live streaming?

Low-latency HLS delivers 2–5 second latency with CMAF parts, scales via standard CDNs, and supports adaptive bitrate streaming. WebRTC offers sub-second latency for true real-time interaction but is harder to scale. LL-HLS suits large audiences; WebRTC is ideal for small, highly interactive sessions.

Conclusion

HLS video is the current standard for any high-quality video content delivery network. It’s widely supported and provides high-definition video with minimal buffering. Furthermore, it can run on almost any server and can be viewed on most devices. For businesses, broadcasters and content creators today, it’s a dream.

You should now have a better understanding of how HLS streaming works, its benefits and when to use it. We’ve also outlined the future of HLS streaming technology, the technicalities and its future. Ultimately, it’s a huge leap forward in video. And with a vast array of live-streaming tools available, such as Dacast’s live streaming platform, taking advantage of HLS has never been easier.

Fortunately, you can take advantage right now. Dacast is a complete video streaming solution for any business, organization or creator. With Dacast’s 14-day free trial, you can try the feature-rich platform and experience the benefits. Signing up is quick, easy and requires no commitments.

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