{"id":955,"date":"2026-04-21T10:27:46","date_gmt":"2026-04-21T03:27:46","guid":{"rendered":"https:\/\/liveapi.com\/blog\/what-is-cmaf\/"},"modified":"2026-04-22T08:39:09","modified_gmt":"2026-04-22T01:39:09","slug":"what-is-cmaf","status":"publish","type":"post","link":"https:\/\/liveapi.com\/blog\/what-is-cmaf\/","title":{"rendered":"What Is CMAF? Common Media Application Format Explained"},"content":{"rendered":"Reading Time: <\/span> 11<\/span> minutes<\/span><\/span>

Before CMAF, streaming a single video to every device meant maintaining two separate sets of encoded files: one for Apple devices using HLS streaming<\/a> with MPEG-TS containers, and another for Android, smart TVs, and browsers using MPEG-DASH with fragmented MP4. That duplication doubled your encoding bill, doubled your storage costs, and doubled the work for your CDN.<\/p>\n

CMAF eliminates that duplication. By standardizing on fragmented MP4 as a single container format that both HLS and MPEG-DASH can read, CMAF lets you encode your video once and deliver it everywhere. You also get a clear path to sub-3-second live latency through chunked transfer encoding \u2014 without switching to WebRTC.<\/p>\n

This guide covers how CMAF works technically, what it means for latency, DRM, and storage costs, and how to decide whether it belongs in your streaming stack.<\/p>\n

What Is CMAF?<\/h2>\n

CMAF (Common Media Application Format) is an international standard for packaging, storing, and delivering segmented media over HTTP. Published by ISO\/IEC in January 2018<\/a> as ISO\/IEC 23000-19, it defines a single media container format \u2014 fragmented MP4 (fMP4) \u2014 that works with both HLS and MPEG-DASH.<\/p>\n

Instead of maintaining separate .ts<\/code> files for HLS and .mp4<\/code> files for DASH, you package your content once into CMAF and serve it through either protocol. Both manifests point to the same media files.<\/p>\n

CMAF is not a streaming protocol<\/strong>. It doesn’t define how media is requested or delivered across the network. It defines how media is structured and packaged. Delivery still happens through HLS or MPEG-DASH manifests \u2014 CMAF just standardizes what those manifests point to.<\/p>\n

The standard was proposed in February 2016 by Apple and Microsoft, who brought the idea to the MPEG working group. Their goal was to cut the industry-wide cost and complexity of delivering video across a fragmented device landscape.<\/p>\n

The Problem CMAF Solves<\/h2>\n

To understand why CMAF matters, you need to understand what streaming looked like before it.<\/p>\n

The Two-Format Problem<\/h3>\n

HLS \u2014 Apple’s HTTP Live Streaming<\/a> protocol \u2014 originally required MPEG-TS (.ts<\/code>) container files for video segments. The MPEG-TS vs HLS comparison<\/a> shows the key technical differences, but the core issue is this: MPEG-DASH, the international standard backed by most non-Apple devices, used fragmented MP4 containers.<\/p>\n

If you wanted to reach both Apple and non-Apple devices with the same content, you had to:<\/p>\n

    \n
  1. Encode your video once<\/li>\n
  2. Package it into MPEG-TS segments for HLS<\/li>\n
  3. Package the same video into fMP4 segments for DASH<\/li>\n
  4. Store both sets of files on your CDN<\/li>\n
  5. Maintain two separate manifest files<\/li>\n<\/ol>\n

    That doubles your storage footprint and CDN bandwidth for no technical reason \u2014 the video data is identical, just wrapped in different containers. According to Bunny.net, CMAF can reduce encoding, packaging, and storage demand by over 70% compared to maintaining both formats.<\/p>\n

    The Latency Ceiling<\/h3>\n

    Traditional HLS was also limited in latency. The protocol buffered complete video segments \u2014 typically 6\u201310 seconds each \u2014 before delivering them to the player. That meant end-to-end latency of 15\u201330 seconds for standard HLS streams.<\/p>\n

    CMAF introduced chunked transfer encoding, which breaks each segment into smaller chunks that the CDN and player can start processing before the full segment is complete. This brings latency down to 2\u20135 seconds with CMAF HLS, and under 2 seconds with Low-Latency HLS (LL-HLS).<\/p>\n

    How CMAF Works<\/h2>\n

    CMAF structures media in a layered hierarchy:<\/p>\n