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Guide · Open source

How to use ffmpeg.wasm: FFmpeg in the browser with JavaScript

Updated · written with AI from the project's own documentation and checked against our catalogue data

ffmpeg.wasm is a WebAssembly and JavaScript port of FFmpeg, the widely used media processing tool. It lets a web page record, convert and stream video and audio inside the browser, so files do not have to be sent to a separate server, according to its README. This guide explains what the project is, how to get started with it, and where it fits, so you can decide whether it suits your page or app.

ffmpeg.wasmffmpegwasm/ffmpeg.wasm · ★ 17.9k · MIT

Quick start

  1. 1Check Node.js. Confirm Node.js is installed, then check the Getting Started docs for the version the project needs.
  2. 2Get the source. Run the git clone command from the README to fetch the repository.
  3. 3Install the package. Follow the Getting Started installation guide to add ffmpeg.wasm to your project.
  4. 4Read the API reference. Open the API docs to see the functions for loading FFmpeg and running media operations.
  5. 5Process media in the browser. Call the API from your page to convert, record or stream audio and video on the user's device.
  6. 6Test for stability. Because the README marks the project as experimental, test your exact use case before relying on it.

What ffmpeg.wasm is and what it does

ffmpeg.wasm is a pure WebAssembly and JavaScript port of FFmpeg. Its README says it enables video and audio recording, conversion and streaming directly inside browsers.

The README documents a JavaScript API. It is a library for developers, not a ready-made end-user application.

  • Port of FFmpeg, written in WebAssembly and JavaScript
  • Runs inside a web browser page
  • Processes media on the user's device, without sending files to a separate server, per the README
  • Licensed under MIT

Check the prerequisites before you start

The only prerequisite named in the README excerpt is Node.js. The README does not state which Node.js version is required, so check the project's getting-started documentation before installing.

The README is marked experimental, so plan for the project's stability limits from the start.

  • Node.js (required version not stated in the README excerpt)
  • Familiarity with FFmpeg concepts helps, since the project is a port of FFmpeg

Get the source and install the package

The README excerpt gives one install command: cloning the repository from GitHub. The install method listed for this project is a package manager, and the README points to the official Getting Started guide for installation details.

Cloning gives you the source code, which you can read or build from. Follow the Getting Started docs for the package install steps.

git clone https://github.com/ffmpegwasm/ffmpeg.wasm

Use the JavaScript API in your page

Your page code calls the ffmpeg.wasm API to load FFmpeg and process media. The README links to the API reference, which lists the available functions and options.

Read the API reference for the exact calls, since the excerpt does not show example code.

  • Open the API reference from the project documentation
  • Process media on the client, then hand the result to your page or upload flow

Know the limits and when to choose another tool

The README labels ffmpeg.wasm as experimental, so it is not a stable, production-proven API. Choose it when browser-side processing is the goal, and avoid it when you need a battle-tested pipeline.

For one-off conversions, a desktop FFmpeg install is the better fit, since this project is framed as a browser port. Comparable projects named for this item include FFmpeg, Mediabunny and Shaka Player.

  • Experimental stability label in the README
  • Desktop FFmpeg is a better fit for one-time conversions
  • Comparable projects: FFmpeg, Mediabunny, Shaka Player

What people use it for

  • Converting a video format inside a browser before upload
  • Recording audio or video in a web page and processing it locally
  • Building an in-browser media editor or upload tool
  • Adding FFmpeg features to a JavaScript project without a server round trip

Frequently asked questions

Is ffmpeg.wasm free to use?

Yes, the project is licensed under MIT, as shown in the README badge and repository. Check the LICENSE file in the repository for the full terms.

What are the requirements for ffmpeg.wasm?

The README excerpt lists Node.js as the prerequisite but does not state a version. Check the Getting Started documentation for the exact requirement.

How do I install ffmpeg.wasm?

The README gives a git clone command for the repository. The project's install method is a package manager, and the Getting Started guide covers the install steps.

Is ffmpeg.wasm production ready?

The README labels the project as experimental, so it does not offer a stable, production-proven API. Test your use case thoroughly before depending on it in production.

What is the difference between ffmpeg.wasm and FFmpeg?

FFmpeg is the widely used desktop media tool. ffmpeg.wasm is a port of it, written in WebAssembly and JavaScript, so it runs inside a browser page instead of a local install.

What are alternatives to ffmpeg.wasm?

Comparable projects named for this item are FFmpeg, Mediabunny and Shaka Player. Use a desktop FFmpeg install for one-off conversions that do not need to run in a browser.

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Our verdict

Choose ffmpeg.wasm if you are a web developer who needs video or audio conversion inside a browser and already knows FFmpeg. Pick a desktop FFmpeg install for one-off file conversions, or another tool if you need a stable, production-proven API or a ready-made app.

Install options & downloads