OpenCaptions

Animated captions for your videos. Open source, self-hosted, and on your iPhone.

Transcribe with Whisper or Parakeet, style every word, and export a burned-in video or subtitle files. Nothing leaves your machine unless you say so.

Documentation · Try it in your browser · Self-host it

Features

• Word-level transcription with Parakeet or Whisper on your machine, the OpenAI API with your own key, or another OpenCaptions server (a GPU box at home, say)
• Animated styles with presets and a full custom panel: fonts, colours, outline, background, animation, position
• A real editor: a timeline to retime captions, fix a misheard word right on the video
• Export a burned-in MP4, WebM or ProRes, SRT, VTT and JSON, or just the captions on a green screen to key out in your video editor
• The preview is the export: one Rust engine draws both, so what you see is what you get
• iPhone, iPad and Mac app with on-device Whisper, Parakeet and Apple Speech, no server and no account
• Many scripts and languages: Latin, Cyrillic, Arabic, Hebrew, Indic, Thai, CJK and more, and an interface in 13 languages
• Private by design: no telemetry, no tracking, accounts are local to your instance

Quick start

You need Docker Compose v2.24 or newer and one file:

curl -O https://raw.githubusercontent.com/leogaudin/opencaptions/main/docker-compose.yml
docker compose up -d

Open http://localhost:5173, create an account, drop a video in.

The compose file runs the edge images (the main branch) until a release exists. Once one does, pin it: OPENCAPTIONS_VERSION=<version> docker compose up -d.

To build from source instead, clone the repository and run docker compose up -d --build (or make up).

The web UI listens on every interface and signup is open. On a shared network or a public host, read Security first.

More

• Documentation: the guides, self-hosting, the HTTP API and the reference. It is plain Markdown in docs/, built into that site with Starlight
• Try it in your browser: the looks on a sample clip, nothing to install
• Self-hosting: installation, configuration, security, GPU acceleration, backups
• Architecture: how it works, including the engine and the iOS app
• iOS app: building and running it
• Contributing: dev setup and the acceptance gate (make ci)
• Security policy: threat model and reporting a vulnerability

Status

Pre-v0.1: under active construction, and APIs and schemas may change until the first tagged release.

License

AGPL-3.0-only. If you offer a hosted version of OpenCaptions, the AGPL requires you to publish your modifications. Contributors accept a CLA so the maintainer can also ship the code where the AGPL cannot go, such as the App Store. Third-party components keep their own licences, see NOTICE.

Built and maintained by Leo Gaudin.

Support the project

OpenCaptions is free and has no tracking. If it is useful to you, you can support it with crypto:

BTC  bc1qac8u7xc5zan6a6fng8gqp7drapau9208d0l9wp
ETH  0xc5C9fE87f10BdC4FecEF9De48cD3ba942640774e
XMR  86bcvPxVaqpTgXuk7FPuJa9sYXbUZnAAFj1sdSiSpr8bWpmW2VhMAF4dzXP2Lead3XFRDurqHnYcKNC2RLPQWvVJ9hbM2Kg