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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.

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 and the TypeScript compiler.

Webpack is used to build the distro bundle and serve the local development environment.


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

The following properties are added to their respective variants' attribute list but are not implemented in their selection and playback.

Playlist tags

The following tags are added to their respective fragment's attribute list but are not implemented in streaming and playback.

Not Supported

For a complete list of issues, see "Top priorities" in the Release Planning and Backlog project tab. Codec support is dependent on the runtime environment (for example, not all browsers on the same OS support HEVC).

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 for more details.

Getting started with development

First, checkout the repository and install the required dependencies

git clone https://github.com/video-dev/hls.js.git
cd hls.js
# After cloning or pulling from the repository, make sure all dependencies are up-to-date
npm install ci
# Run dev-server for demo page (recompiles on file-watch, but doesn't write to actual dist fs artifacts)
npm run dev
# After making changes run the sanity-check task to verify all checks before committing changes
npm run sanity-check

The dev server will host files on port 8000. Once started, the demo can be found running at http://localhost:8000/demo/.

Before submitting a PR, please see our contribution guidelines. Join the discussion on Slack via video-dev.org in #hlsjs for updates and questions about development.

Build tasks

Build all flavors (suitable for prod-mode/CI):

npm install ci
npm run build

Only debug-mode artifacts:

npm run build:debug

Build and watch (customized dev setups where you'll want to host through another server than webpacks' - for example in a sub-module/project)

npm run build:watch

Only specific flavor (known configs are: debug, dist, light, light-dist, demo):

npm run build -- --env dist # replace "dist" by other configuration name, see above ^

Note: The "demo" config is always built.

NOTE: hls.light.*.js dist files do not include EME, subtitles, CMCD, or alternate-audio support. In addition, the following types are not available in the light build:

Linter (ESlint)

Run linter:

npm run lint

Run linter with auto-fix mode:

npm run lint:fix

Run linter with errors only (no warnings)

npm run lint:quiet

Formatting Code

Run prettier to format code

npm run prettier

Type Check

Run type-check to verify TypeScript types

npm run type-check

Automated tests (Mocha/Karma)

Run all tests at once:

npm test

Run unit tests:

npm run test:unit

Run unit tests in watch mode:

npm run test:unit:watch

Run functional (integration) tests:

npm run test:func


An overview of this project's design, it's modules, events, and error handling can be found here.

API docs and usage guide

Note you can access the docs for a particular version using "https://github.com/video-dev/hls.js/tree/deployments"


Latest Release




Specific Version

Find the commit on https://github.com/video-dev/hls.js/tree/deployments.


HLS.js is only compatible with browsers supporting MediaSource extensions (MSE) API with 'video/MP4' mime-type inputs.

HLS.js is supported on:

A Promise polyfill is required in browsers missing native promise support.

Please note: iOS Safari on iPhone does not support the MediaSource API. This includes all browsers on iOS as well as apps using UIWebView and WKWebView.

Safari browsers (iOS, iPadOS, and macOS) have built-in HLS support through the plain video "tag" source URL. See the example below (Using HLS.js) to run appropriate feature detection and choose between using HLS.js or natively built-in HLS support.

When a platform has neither MediaSource nor native HLS support, the browser cannot play HLS.

Keep in mind that if the intention is to support HLS on multiple platforms, beyond those compatible with HLS.js, the HLS streams need to strictly follow the specifications of RFC8216, especially if apps, smart TVs, and set-top boxes are to be supported.

Find a support matrix of the MediaSource API here: https://developer.mozilla.org/en-US/docs/Web/API/MediaSource

Using HLS.js


Prepackaged builds are included with each release. Or install the hls.js as a dependency of your project:

npm install --save hls.js

A canary channel is also available if you prefer to work off the development branch (master):

npm install hls.js@canary

Embedding HLS.js

Directly include dist/hls.js or dist/hls.min.js in a script tag on the page. This setup prioritizes HLS.js MSE playback over native browser support for HLS playback in HTMLMediaElements:

Alternative setup

To check for native browser support first and then fallback to HLS.js, swap these conditionals. See this comment to understand some of the tradeoffs.

For more embed and API examples see docs/API.md.


All HLS resources must be delivered with CORS headers permitting GET requests.

Video Control

Video is controlled through HTML <video> element HTMLVideoElement methods, events and optional UI controls (<video controls>).

Player Integration

The following players integrate HLS.js for HLS playback:

They use HLS.js in production!


Chrome/Firefox integration

made by gramk, plays hls from address bar and m3u8 links


HLS.js is released under Apache 2.0 License