# Kagami/ffmpeg.js

Port of FFmpeg with Emscripten

Repository: https://github.com/Kagami/ffmpeg.js
Canonical: https://ross.abutalabs.com/products/ffmpegjs
Language: JavaScript
License: NOASSERTION
License Family: other
Topics: ffmpeg, webm, emscripten
Last push: 2023-11-04T22:20:41+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 4067, "days_push": 1033, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases, no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 3460, forks 341 (observed 2026-08-28T04:08:05.630037+00:00)

## What it is
FFmpeg compiled to JavaScript/WebAssembly via Emscripten, optimized for in-browser use with WebM and MP4 builds plus Web Worker wrappers. It lets JavaScript applications run FFmpeg transcoding without a server, and also works in Node.

## Use cases
- transcode video to webm or mp4 entirely in the browser
- run ffmpeg commands client-side without a backend
- extract audio from video files in a web app
- offload media encoding to a web worker
- convert uploaded video files before sending them to a server

## When to choose
- you need client-side video/audio transcoding with no server round-trip
- you want a small, browser-optimized FFmpeg build for WebM or MP4
- you need the same FFmpeg code to run in both browser and Node

## When to avoid
- you need codecs beyond the bundled WebM/MP4 builds
- you need actively maintained releases or the latest FFmpeg features
- you need high-performance native-speed encoding on a server

## Facets
- artifact type: library
- maturity: maintenance
- function: video-processing, audio-processing, wasm
- domain: media, web-development, frontend
- platform: browser, wasm
- tags: ffmpeg, emscripten, asm-js, web-worker, transcoding, webm, mp4, nodejs

## Member repositories
- Kagami/ffmpeg.js (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:05.630037+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T18:36:55.923907+00:00, confidence not recorded.
  - readme: https://github.com/Kagami/ffmpeg.js (fetched 2026-08-28T04:08:05.630037+00:00, sha 3c7eabaf09b9)
  - registry_npm: https://registry.npmjs.org/ffmpeg.js (fetched 2026-08-29T09:31:14.372483+00:00, sha 1b98203e73cd)
- Data as of 2026-08-30T08:39:29.467469+00:00.