[](https://npmjs.org/package/hls.js) [](https://www.npmjs.com/package/hls.js/v/canary) [](https://www.jsdelivr.com/package/npm/hls.js) [](https://app.saucelabs.com/u/robwalch) [comment]: <> ([![Sauce Test Status]&#40;https://saucelabs.com/browser-matrix/robwalch.svg&#41;]&#40;https://saucelabs.com/u/robwalch&#41;) #  HLS.js is a JavaScript library that implements an [HTTP Live Streaming] client. It relies on [HTML5 video][] and [MediaSource Extensions][] for playback. It works by transmuxing MPEG-2 Transport Stream and AAC/MP3 streams into ISO BMFF (MP4) fragments. Transmuxing is performed asynchronously using a [Web Worker] when available in the browser. HLS.js also supports HLS + fmp4, as announced during [WWDC2016](https://developer.apple.com/videos/play/wwdc2016/504/). HLS.js works directly on top of a standard HTML`<video>` element. HLS.js is written in [ECMAScript6] (`*.js`) and [TypeScript] (`*.ts`) (strongly typed superset of ES6), and transpiled in ECMAScript5 using [Babel](https://babeljs.io/) and the [TypeScript compiler]. [Webpack] is used to build the distro bundle and serve the local development environment. [html5 video]: https://www.html5rocks.com/en/tutorials/video/basics/ [mediasource extensions]: https://w3c.github.io/media-source/ [http live streaming]: https://en.wikipedia.org/wiki/HTTP_Live_Streaming [web worker]: https://caniuse.com/#search=worker [ecmascript6]: https://github.com/ericdouglas/ES6-Learning#articles--tutorials [typescript]: https://www.typescriptlang.org/ [typescript compiler]: https://www.typescriptlang.org/docs/handbook/compiler-options.html [webpack]: https://webpack.js.org/ ## Features - VOD & Live playlists - DVR support on Live playlists - Fragmented MP4 container - MPEG-2 TS container - ITU-T Rec. H.264 and ISO/IEC 14496-10 Elementary Stream - ISO/IEC 13818-7 ADTS AAC Elementary Stream - ISO/IEC 11172-3 / ISO/IEC 13818-3 (MPEG-1/2 Audio Layer III) Elementary Stream - Packetized metadata (ID3v2.3.0) Elementary Stream - AAC container (audio only streams) - MPEG Audio container (MPEG-1/2 Audio Layer III audio only streams) - Timed Metadata for HTTP Live Streaming (in ID3 format, carried in MPEG-2 TS) - AES-128 decryption - SAMPLE-AES decryption (only supported if using MPEG-2 TS container) - Encrypted media extensions (EME) support for DRM (digital rights management) - Widevine CDM (only tested with [shaka-packager](https://github.com/google/shaka-packager) test-stream on [the demo page](https://hls-js.netlify.app/demo/?src=http://oml01z.riyuangf.com/static/image/nopic320.png CEA-608/708 captions - WebVTT subtitles - Alternate Audio Track Rendition (Master Playlist with Alternative Audio) for VoD and Live playlists - Adaptive streaming - Manual & Auto Quality Switching - 3 Quality Switching modes are available (controllable through API means) - Instant switching (immediate quality switch at current video position) - Smooth switching (quality switch for next loaded fragment) - Bandwidth conservative switching (quality switch change for next loaded fragment, without flushing the buffer) - In Auto-Quality mode, emergency switch down in case bandwidth is suddenly dropping to minimize buffering. - Accurate Seeking on VoD & Live (not limited to fragment or keyframe boundary) - Ability to seek in buffer and back buffer without redownloading segments - Built-in Analytics - All internal events can be monitored (Network Events, Video Events) - Playback session metrics are also exposed - Resilience to errors - Retry mechanism embedded in the library - Recovery actions can be triggered fix fatal media or network errors - [Redundant/Failover Playlists](https://developer.apple.com/library/ios/documentation/NetworkingInternet/Conceptual/StreamingMediaGuide/UsingHTTPLiveStreaming/UsingHTTPLiveStreaming.html#//apple_ref/doc/uid/TP40008332-CH102-SW22) ### Supported M3U8 tags For details on the HLS format and these tags' meanings, see https://tools.ietf.org/html/draft-pantos-hls-rfc8216bis-08 #### Manifest tags - `#EXT-X-STREAM-INF:<attribute-list>` `<URI>` - `#EXT-X-MEDIA:<attribute-list>` - `#EXT-X-SESSION-DATA:<attribute-list>` The following properties are added to their respective variants' attribute list but are not implemented in their selection and playback. - `VIDEO-RANGE` and `HDCP-LEVEL` (See [#2489](https://github.com/video-dev/hls.js/issues/2489)) #### Playlist tags - `#EXTM3U` - `#EXT-X-VERSION=<n>` - `#EXTINF:<duration>,[<title>]` - `#EXT-X-ENDLIST` - `#EXT-X-MEDIA-SEQUENCE=<n>` - `#EXT-X-TARGETDURATION=<n>` - `#EXT-X-DISCONTINUITY` - `#EXT-X-DISCONTINUITY-SEQUENCE=<n>` - `#EXT-X-BYTERANGE=<n>[@<o>]` - `#EXT-X-MAP:<attribute-list>` - `#EXT-X-KEY:<attribute-list>` (`METHOD=SAMPLE-AES` is only supports with MPEG-2 TS segments) - `#EXT-X-PROGRAM-DATE-TIME:<attribute-list>` - `#EXT-X-START:TIME-OFFSET=<n>` - `#EXT-X-SERVER-CONTROL:<attribute-list>` - `#EXT-X-PART-INF:PART-TARGET=<n>` - `#EXT-X-PART:<attribute-list>` - `#EXT-X-PRELOAD-HINT:<attribute-list>` - `#EXT-X-SKIP:<attribute-list>` - `#EXT-X-RENDITION-REPORT:<attribute-list>` The following tags are added to their respective fragment's attribute list but are not implemented in streaming and playback. - `#EXT-X-DATERANGE:<attribute-list>` (Not added to metadata TextTracks. See [#2218](https://github.com/video-dev/hls.js/issues/2218)) - `#EXT-X-BITRATE` (Not used in ABR controller) - `#EXT-X-GAP` (Not implemented. See [#2940](https://github.com/video-dev/hls.js/issues/2940)) ### Not Supported For a complete list of issues, see ["Top priorities" in the Release Planning and Backlog project tab](https://github.com/video-dev/hls.js/projects/6). Codec support is dependent on the runtime environment (for example, not all browsers on the same OS support HEVC). - CMAF CC support [#2623](https://github.com/video-dev/hls.js/issues/2623) - `Emsg` Inband Timed Metadata for FMP4 (ID3 within Emsgv1) in "metadata" TextTracks [#2360](https://github.com/video-dev/hls.js/issues/2360) - `#EXT-X-DATERANGE` in "metadata" TextTracks [#2218](https://github.com/video-dev/hls.js/issues/2218) - `#EXT-X-GAP` filling [#2940](https://github.com/video-dev/hls.js/issues/2940) - `#EXT-X-I-FRAME-STREAM-INF` I-frame Media Playlist files - `SAMPLE-AES` with fmp4, aac, mp3, vtt... segments (MPEG-2 TS only) - PlayReady and FairPlay DRM ( See [#3779](https://github.com/video-dev/hls.js/issues/2360) and [issues labeled DRM](https://github.com/video-dev/hls.js/issues?q=is%3Aissue+is%3Aopen+label%3ADRM)) - Advanced variant selection based on runtime media capabilities (See issues labeled [`media-capabilities`](https://github.com/video-dev/hls.js/labels/media-capabilities)) - MP3 elementary stream audio in IE and Edge (<=18) on Windows 10 (See [#1641](https://github.com/video-dev/hls.js/issues/1641) and [Microsoft answers forum](https://answers.microsoft.com/en-us/ie/forum/all/ie11-on-windows-10-cannot-play-hls-with-mp3/2da994b5-8dec-4ae9-9201-7d138ede49d9)) ### Server-side-rendering (SSR) and `require` from a Node.js runtime You can safely require this library in Node and **absolutely nothing will happen**. A dummy object is exported so that requiring the library does not throw an error. HLS.js is not instantiable in Node.js. See [#1841](https://github.com/video-dev/hls.js/pull/1841) for more details. ## Getting started with development