Multi-Converter is a free and open source tool to convert your files directly on your computer.
Documents, images, audio and video — no account, no cloud, no file upload to any server.
- Why use Multi-Converter?
- Download
- macOS Installation
- Linux Installation
- Overview
- Supported Formats
- Privacy
- Bundled Conversion Engines
- Licenses
- Legal Notice
- Development
- Contact
- Contributing
- Code of Conduct
- Security
- Star History
| Key point | What it means for you |
|---|---|
| 🆓 Free and open source | Use Multi-Converter freely and browse its source code. |
| 🔒 Local and private | Your files stay on your computer throughout the conversion. |
| 🔄 Multi-format | Documents, images, audio and video — all handled in a single app. |
| ⚡ Ready after install | Conversions run locally with the engines bundled for each release platform. |
| System | Status | Download |
|---|---|---|
| 🪟 Windows x64 | ✅ Available | .exe |
| 🍎 macOS Apple Silicon + Intel | ✅ Available | .dmg |
| 🐧 Linux x64 | ✅ Available | .AppImage |
The macOS direct download uses the stable latest asset Multi-Converter_macos-universal.dmg. Each release also keeps the versioned DMG asset Multi-Converter_X.Y.Z_macos-universal.dmg for traceability.
The Linux direct download uses the stable latest asset Multi-Converter_linux-x64.AppImage. Each release also keeps the versioned AppImage asset Multi-Converter_X.Y.Z_linux-x64.AppImage for traceability.
The macOS build is a universal DMG for both Apple Silicon and Intel Macs.
Download Multi-Converter_macos-universal.dmg for the latest macOS release. The same release also includes the versioned asset Multi-Converter_X.Y.Z_macos-universal.dmg.
This macOS build is not Apple-signed and not notarized. On first launch, macOS may block it. To open it safely:
- Open
Multi-Converter.apponce from Applications. - Go to
System Settings > Privacy & Security. - Choose
Open Anyway, then confirmOpen.
This approval is normally needed only on the first launch for that downloaded app copy, or after installing a new version. macOS automatic updates are enabled for builds that include the Tauri updater-signed artifacts.
Download Multi-Converter_linux-x64.AppImage for the latest Linux x64 release.
Most Linux desktops need the AppImage to be marked executable once:
chmod a+x Multi-Converter_linux-x64.AppImage
./Multi-Converter_linux-x64.AppImageLinux automatic updates are enabled for builds that include the Tauri updater-signed AppImage artifact.
Multi-Converter detects the formats listed below and offers compatible conversions based on the available engines.
| Category | Recognized formats |
|---|---|
| 📄 Documents & text | PDF, DOCX, DOC, TXT/LOG, HTML/HTM, CSV, JSON, ODT, RTF, Markdown/MD, EPUB, XML |
| 🖼️ Images | PNG, JPEG/JPG, GIF, SVG, WebP, TIFF/TIF, BMP, ICO |
| 🎵 Audio | MP3, AAC/M4A, FLAC, WAV, OGG/OGA, WMA, OPUS, AIFF/AIF, ALAC, AC3, MP2, AMR, AU/SND, CAF |
| 🎬 Video | MP4/M4V, MKV, WebM, MOV, AVI, WMV, 3GP/3G2, MTS/M2TS, MPEG-2/MPG/MPEG, OGV |
Note Some formats may be recognized without supporting every possible conversion to every other format. The options shown in the app depend on the source file and the available engines. AMR output is currently Windows-only because the staged macOS FFmpeg build does not include the OpenCORE AMR encoder.
Conversions run on your machine. An internet connection may be required to download the app or install an update, but Multi-Converter never sends your files to the cloud.
The Windows x64 installer and macOS universal DMG bundle third-party engines for Office, PDF, Markdown/HTML/EPUB and advanced image conversions, so users do not need a separate download after setup. Linux AppImage releases must pass the Linux engine checklist before claiming the same advanced document/PDF/image coverage.
Full Windows x64 installation as declared in the manifest, sizes rounded. macOS bundle sizes may differ:
| Engine | Mainly used for | Download | Once installed | License |
|---|---|---|---|---|
| PDFium | PDF to image rendering | 5.6 MB | 13.1 MB | BSD-3-Clause |
| LibreOffice headless | Accurate Office and PDF conversions | 483.8 MB | 1.51 GB | MPL-2.0 |
| Pandoc | Markdown, HTML, EPUB, DOCX | 40.7 MB | 231.1 MB | GPL-2.0-or-later |
| libvips | Advanced images | 10.8 MB | 28.5 MB | LGPL-2.1-or-later |
| Total | Bundled advanced engines | 540.9 MB | 1.79 GB | Multiple licenses |
Multi-Converter's code is licensed under the GNU Affero General Public License v3.0 or later (AGPL-3.0-or-later). See LICENSE.
Multi-Converter uses third-party conversion engines that retain their own licenses, notices and redistribution conditions. They do not change license because you use them through Multi-Converter.
Key points:
- Multi-Converter itself is licensed under AGPL-3.0-or-later.
- Third-party engines remain separate software with their own licenses.
- The Windows x64 V1 release bundles FFmpeg and ffprobe
8.1.1-essentials_build-www.gyan.dev, built with--enable-gpl: the bundled executables are treated as third-party software covered by the GPL in this distribution. - The Windows x64 installer and macOS universal DMG bundle PDFium, LibreOffice, Pandoc and libvips, each under their own license. Linux advanced engine redistribution must be verified separately before public release notes claim full Linux document/PDF/image coverage.
See NOTICE and docs/THIRD_PARTY_ENGINES.md for details.
This documentation is not legal advice. Release maintainers must verify the exact obligations of the binaries and third-party engines they distribute.
This section is for anyone who wants to run the project locally, fix a bug, suggest an improvement, or explore the code. Releases, installers, engine archives and release notes are prepared by the project maintainers.
| Layer | Technology |
|---|---|
| Desktop application | Tauri 2 |
| UI | React + TypeScript |
| Backend | Rust + Cargo |
| Frontend build | Vite |
| Internal scripts | Node.js |
- Windows x64 for Windows development and packaging.
- macOS 11 or newer with Xcode Command Line Tools is required for macOS packaging and validation.
- Linux x64 with WebKitGTK 4.1 development packages is required for Linux AppImage packaging and host validation.
- Node.js
>=24 <25and npm>=11 <12. - Rust and Cargo.
- The Tauri prerequisites for Windows.
git clone https://github.com/Amix29/Multi-Converter.git
cd Multi-Converter
npm install# Full desktop app: Tauri, real conversions, sidecars
npm start
# Equivalent command
npm run tauri:dev
npm run devonly starts the Vite frontend with a simulated API. To test real conversions, sidecars, the Tauri runtime or file system access, usenpm startornpm run tauri:dev.
Recommended checks before a pull request:
npm run check
npm run test:rust
npm run test:pdfium-wrapper
npm run test:pdfium-wrapper:compilenpm run check covers installer asset generation, bundled engine validation, embedded manifest validation, i18n validation, TypeScript typechecking and engine packaging validation.
Targeted commands useful during development:
npm run typecheck
npm run validate:i18n
npm run validate:embedded-manifest
npm run validate:bundled-engines
npm run validate:enginesBuild:
npm run build
npm run tauri:build
# macOS only, from a Mac with both Darwin sidecar architectures staged.
# prepare:bundled-engines creates the universal sidecars required by Tauri.
# The wrapper refuses this command on Windows/Linux so a DMG is never presented as cross-built.
npm run tauri:build:macos
# Linux x64 only, from a Linux host with real Linux sidecars staged.
npm run tauri:build:linuxRust formatting and linting:
npm run fmt:rust:check
npm run clippy:rust
npm run clippy:pdfium-wrapperOn Windows PowerShell, direct Cargo commands can also use a temporary build folder:
cargo fmt --manifest-path src-tauri/Cargo.toml
cargo test --manifest-path src-tauri/Cargo.toml --target-dir "$env:TEMP\mc-cargo-target-engine-registry"npm run tauri:dev and npm run tauri:build use a temporary CARGO_TARGET_DIR to avoid stale Tauri artifacts in src-tauri/target.
src/ React UI
src/i18n/ UI translations
src-tauri/ Tauri/Rust backend
src-tauri/tauri.macos.conf.json
src-tauri/binaries/ Base sidecars bundled for the current release target
src-tauri/engines-manifest.json
docs/ License, security and third-party engine documentation
tools/ Engine technical configuration
scripts/ Build, validation and maintenance scripts
Generated folders (dist, node_modules, build caches, local engine sources, engine archives, test results) must not be committed.
Multi-Converter works with bundled engine groups:
| Group | Role | Distribution |
|---|---|---|
| Base | Common conversions available with the app | Integrated engines or bundled sidecars |
| Advanced | More accurate or more advanced conversions | Bundled Tauri resources prepared from verified engine ZIPs |
The Windows x64 base engines ffmpeg and ffprobe are bundled in src-tauri/binaries. Advanced engines are prepared into src-tauri/bundled-engines and bundled as Tauri resources. Both groups are validated before each build.
The macOS universal DMG must include universal FFmpeg/ffprobe sidecars. Advanced macOS engines must not be advertised unless the release workflow stages reviewed macos-universal entries with verified archives, licenses, notices and checksums and the final DMG passes macOS validation.
Restore and validate the bundled engines:
npm run prepare:bundled-engines
npm run validate:bundled-enginesTo work locally on engine scripts, place temporary sources under:
engine-sources/windows-x64/<engineId>/
engine-sources/macos-universal/<engineId>/
Important Do not commit generated archives, local engine sources, release checksums, DMGs or engine version changes without explicit approval from a maintainer. macOS app bundles and DMGs must be rebuilt from source/config; do not hand-edit the generated
.appafter packaging.
See tools/ENGINE_PACKAGING.md and docs/THIRD_PARTY_ENGINES.md for technical context.
For the platform test split, see docs/TESTING.md.
For repository discoverability topics, see docs/GITHUB_TOPICS.md.
For general questions, feedback or partnership requests, contact amixdigital0@gmail.com.
Contributions are welcome. Read CONTRIBUTING.md before opening a pull request.
Expected contributions include bug fixes, optimizations, UI improvements, translations, tests and feature suggestions. Before submitting a change, run the checks relevant to the area you modified.
Multi-Converter is an open source project. Everyone is expected to participate with respect, clarity and good faith.
- Be respectful and welcoming to contributors of all experience levels.
- Keep discussions constructive, technical when possible, and focused on the project.
- When reporting a bug, include what happened, what you expected, and how to reproduce it.
- When reviewing code, focus on the change, the behavior, and concrete improvements.
- Harassment, insults, discriminatory language, personal attacks or threats.
- Spam, repeated off-topic messages, advertising, or low-effort comments that disrupt the project.
- Deliberately misleading reports, hostile reviews, or behavior intended to waste maintainer time.
- Sharing private information without permission.
Maintainers may edit, hide or remove comments, close discussions, or block users when behavior harms the project or its contributors.
To report a vulnerability or security issue, use GitHub private vulnerability reporting when available. Do not post exploit details, crafted files or sensitive logs in a public issue. See SECURITY.md for scope and safe reporting instructions.