Overview
Multi-Converter is a free and open-source Windows file converter. It converts documents, data files, images, audio and video directly on the user's computer, without requiring an account, a subscription or mandatory upload to a cloud conversion service.
Official project links
Open-source hosting platform used by the project.
External referenceMulti-Converter repositoryPublic source code, issues and project files.
External referenceMulti-Converter releasesLatest Windows release and release history.
External referenceAmix Digital on YouTubeCreator channel for product updates and related content.
Recognized formats
Recognized formats do not mean every source format can be converted to every target format. The app shows available conversions based on the source file, the target format and the engines installed locally.
| Category | Recognized formats |
|---|---|
| Documents and text | PDF, DOCX, TXT, LOG, HTML, HTM, CSV, JSON, ODT, RTF, Markdown, EPUB and XML |
| Images | PNG, JPEG, JPG, SVG, WebP, TIFF, TIF, BMP and ICO |
| Audio | MP3, AAC, M4A, FLAC, WAV, OGG, OGA, WMA, OPUS, AIFF, ALAC, AC3, MP2, AMR, AU, SND and CAF |
| Video | MP4, M4V, MKV, WebM, MOV, AVI, WMV, 3GP, 3G2, MTS, M2TS, MPEG-2, MPG, MPEG and OGV |
Local conversion and privacy
Supported conversions run on the user's machine. Internet access can be used to download the app, retrieve updates, open the GitHub repository or install the optional Maximum Quality extension, but local conversions do not require mandatory file upload.
Conversion engines
| Engine tier | Role |
|---|---|
| Base engines | Common conversions available with the app through integrated engines or bundled sidecars. |
| FFmpeg and ffprobe | Bundled on Windows x64 for audio and video conversion support. |
| Maximum Quality extension | Optional engine package for more accurate Office, PDF, Markdown, HTML, EPUB and advanced image conversions. |
| PDFium | Optional PDF rendering engine used for PDF-to-image workflows. |
| LibreOffice headless | Optional engine for more accurate Office document and PDF conversions. |
| Pandoc | Optional engine for Markdown, HTML, EPUB and DOCX workflows. |
| libvips | Optional engine for advanced image processing. |
Development stack
The desktop app is built with a Tauri 2 shell, a React and TypeScript interface, a Rust backend, Cargo tooling, Vite for frontend builds and Node.js for scripts.
Desktop app framework used for the Windows application shell.
External referenceReactUI library used to build the application interface.
External referenceTypeScriptTyped JavaScript used across the frontend code.
External referenceRustSystems language used by the Tauri backend.
External referenceCargoRust package manager and build tool.
External referenceViteFrontend build tool used during development.
External referenceNode.jsRuntime used for npm scripts and project tooling.
Useful developer commands
| Task | Command |
|---|---|
| Install dependencies | npm install |
| Run the real desktop app | npm start |
| Equivalent Tauri dev command | npm run tauri:dev |
| Run the full project check | npm run check |
| Typecheck the frontend | npm run typecheck |
| Validate bundled base engines | npm run validate:bundled-base-engines |
| Build the frontend | npm run build |
| Build the Tauri app | npm run tauri:build |
Licenses and third-party engines
Multi-Converter's own code is published under AGPL-3.0-or-later. Third-party conversion engines keep their own licenses, notices and redistribution conditions. Users and contributors should verify release files, engine archives and license notices from the official repository before redistribution.