Transmute is a free, open source, self-hosted file converter built for privacy and flexibility. Convert images, video, audio, documents, spreadsheets, subtitles, and fonts entirely locally, with no file size limits and no third-party access to your files. Deploy in seconds with Docker.
Full documentation on our website!
| Converter / Home | Uploaded Files | Previously Converted | Settings |
|---|---|---|---|
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This application is currently in early beta. Want to support us or follow along? Give us a star or jump in and contribute!
Note
This project is human-led and maintainer-reviewed.
AI tools assist during development (autocomplete, some boilerplate, help with tests) but all code is intentionally written, reviewed, and validated by a human who understands and takes responsibility for the result. This is not an autonomously generated project, and fully AI-generated or agent-submitted contributions are not accepted. See the contributing guide for more details
Want to see a video demo? Check out our YouTube.
- Privacy first: Files are processed on your own server and never sent to third parties
- No file size limits: Convert files as large as your storage allows
- 100+ formats supported: Images, video, audio, documents, spreadsheets, subtitles, and fonts
- Built-in authentication: User accounts, role-based access, and API key support out of the box
- Docker ready: Deploy with a single command, no complex setup required
- REST API: Automate and integrate file conversions via the built-in OpenAPI-documented API
- Multiple themes: Seven built-in light and dark UI themes
Warning
Think carefully before exposing Transmute to the public internet / WAN. Transmute includes built-in authentication and per-user data isolation, but is designed for trusted networks. If you expose it beyond your LAN, place it behind a reverse proxy with TLS and rate limiting. The maintainers are not responsible for security issues arising from your deployment configuration.
wget "https://raw.githubusercontent.com/transmute-app/transmute/refs/heads/main/docker-compose.yml" && docker compose up -dThen visit localhost:3313
Full "Getting Started" guide: https://transmute.sh/docs/getting-started/
For the record, I love all of these services and use them all frequently. Transmute is not up to par with any of them yet. But it will be!
| Service | Why Replace? |
|---|---|
| cloudconvert.com | File size limits, API is paid only, 3rd-party gets my files |
| freeconvert.com | File size limits, 3rd-party gets my files |
| convertio.co | File size limits, 3rd-party gets my files |
| Category | Formats |
|---|---|
| Images | JPEG, PNG, WebP, AVIF, HEIC/HEIF, JXL, GIF, BMP, TIFF, SVG, ICO, PSD, and more |
| Video | MP4, MKV, MOV, WebM, AVI, FLV, WMV, TS, 3GP, and more |
| Audio | MP3, WAV, FLAC, AAC, M4A, OPUS, OGG, AIFF, WMA, and more |
| Documents | Markdown, HTML, DOCX, PDF, EPUB, ODT, RST, LaTeX, RTF, PPTX, and more |
| Data / Spreadsheets | CSV, XLSX, JSON, TOON, Parquet, YAML, TSV, XML, ODS, and more |
| Subtitles | SRT, ASS, SSA, VTT, SUB |
| Fonts | TTF, OTF, WOFF, WOFF2 |
| Diagrams | DrawIO |
| Dark Theme | Screenshot | Light Theme | Screenshot |
|---|---|---|---|
| Rubedo (Default) |  |
Albedo |  |
| Citrinitas |  |
Aurora |  |
| Viriditas |  |
Caelum |  |
| Nigredo |  |
Argentum |  |
When the app is running the API docs are available at http://TRANSMUTE_IP:3313/api/docs
Contributions are welcome! This project is human-driven - autonomous agents and AI assistants are not welcome contributors and such submissions will be rejected. See the contributing guide for details.