Free Local File Converter for Windows 10 & 11
Just Converter
Most file converters make you upload your files to a website and wait for a server to process them. Just Converter does the opposite — it runs entirely on your own machine, processes every file locally, and never sends anything to a server. Video, audio, images, documents, and PDFs: all converted privately on your device with no account required.
Just Converter Screenshots & Interface
What is Just Converter?
Just Converter is a free, open source local file converter for Windows 10 and Windows 11, developed by Osenpa and released under the MIT License. It converts video, audio, images, and PDF documents entirely on the user's own device using FFmpeg and libvips — no files are uploaded to any server, and no internet connection is required for conversion. Supported formats include video (MP4, AVI, MKV, MOV, WMV, WEBM, animated GIF), audio (MP3, WAV, FLAC, AAC, OGG, WMA, M4A, OPUS), images (JPG, PNG, WEBP, AVIF, BMP, TIFF, GIF, ICO, HEIC), and PDF workflows (merge, split, export pages as images, create PDF from images). Just Converter supports batch conversion with drag-and-drop file reordering, custom output naming patterns, and 16 interface languages. It is available as a Setup Installer and as a no-install Portable ZIP, at no cost, with no subscription and no account required.
Just Converter vs. Other File Converters
| Feature | Just Converter | CloudConvert | SmallPDF | HandBrake | FFmpeg (CLI) |
|---|---|---|---|---|---|
| Local processing (no uploads) | Yes — 100% offline | No — cloud-based | No — cloud-based | Yes | Yes |
| Graphical interface (no CLI) | Yes | Yes (web UI) | Yes (web UI) | Yes | No — command line only |
| Video conversion | Yes (MP4, AVI, MKV, MOV, WEBM, WMV) | Yes | No | Yes | Yes |
| Image conversion (incl. HEIC, AVIF) | Yes | Yes | No | No | Partial |
| PDF tools (merge, split, export) | Yes | Yes | Yes | No | No |
| Batch conversion | Yes | Yes (paid plan for large batches) | Limited (free tier) | Yes | Yes (via scripting) |
| File size limits | None (limited only by your hardware) | Yes (free plan: 1 GB) | Yes (free plan: 2 MB PDF) | None | None |
| Free to use | Yes — fully free | Freemium (limited free tier) | Freemium (limited free tier) | Yes — fully free | Yes — fully free |
| Open source | Yes (MIT) | No | No | Yes (GPL-2.0) | Yes (LGPL-2.1) |
Why Just Converter — Not a Website
Online converters are convenient until they aren't. File size limits, upload queues, unclear data retention, and files being processed on someone else's server are all tradeoffs that come with browser-based tools. Just Converter is the opposite kind of experience: a native Windows desktop app that runs entirely on your own machine, processes every file locally, and works offline for all standard conversion workflows. Available as a Setup Installer or a no-install Portable ZIP.
Core Features
- Fully Local Processing: Every conversion runs on your own device. Files are never uploaded to any server. Just Converter does not require an internet connection for ordinary conversion workflows.
- Video Conversion: Convert between MP4, AVI, MKV, MOV, WMV, and WEBM. Export animated GIF output. Extract audio from video files. Remuxing is used where possible to preserve quality without re-encoding.
- Audio Conversion: Convert between MP3, WAV, FLAC, AAC, OGG, WMA, M4A, and OPUS. Audio can also be exported directly from supported video inputs.
- Image Conversion: Convert between JPG, PNG, WEBP, AVIF, BMP, TIFF, GIF, ICO, and HEIC. Convert individual images to PDF or combine multiple images into a single PDF.
- Document & PDF Tools: Convert across TXT, DOCX, PDF, HTML, EPUB, MD, CSV, XLSX, and PPTX. Merge multiple PDFs into one file. Split a PDF into separate pages. Export PDF pages as JPG, PNG, or WEBP. Multi-page output can be saved as separate files or packed into a ZIP archive.
- Batch Productivity: Convert multiple files in one run. Reorder files with drag-and-drop or move up/down controls. Add more files after the initial selection. Use custom naming patterns for batch output. Recent output folders and last-used settings are remembered between sessions.
- 16-Language Support: Natively available in English, Türkçe, Deutsch, Français, Español, Português, Italiano, العربية, 中文, 日本語, 한국어, हिन्दी, Bahasa Indonesia, Русский, עברית, and Tiếng Việt — with automatic system language detection.
Frequently Asked Questions
- Is Just Converter completely free?
- Yes. Just Converter is 100% free. There are no paid tiers, subscriptions, or premium features. It is available on the Microsoft Store and via direct download at no cost.
- Does Just Converter upload my files to the cloud?
- No. Just Converter processes everything locally on your device. Files are never sent to any server. All conversion happens on your own machine without an internet connection.
- What file formats does Just Converter support?
- Just Converter supports video formats (MP4, AVI, MKV, MOV, WMV, WEBM, GIF), audio formats (MP3, WAV, FLAC, AAC, OGG, WMA, M4A, OPUS), image formats (JPG, PNG, WEBP, AVIF, BMP, TIFF, GIF, ICO, HEIC), and document/PDF workflows (TXT, DOCX, PDF, HTML, EPUB, MD, CSV, XLSX, PPTX).
- What Windows versions does Just Converter support?
- Just Converter supports Windows 10 and Windows 11 (64-bit). It is a native WPF desktop application built on .NET 8.
- Can Just Converter convert multiple files at once?
- Yes. Just Converter is built for batch workflows. You can add multiple files, reorder them with drag-and-drop or move up/down controls, add more files after the initial selection, and use batch naming patterns for multi-file output.
- What PDF tools are included?
- Just Converter includes dedicated PDF tools: merge multiple PDFs into a single file, split a PDF into separate pages, export PDF pages as JPG/PNG/WEBP images, and create a PDF from multiple images. Multi-page output can be exported as separate files or as a ZIP archive.
- How many languages does Just Converter support?
- Just Converter is available in 16 languages: English, Turkish, German, French, Spanish, Portuguese, Italian, Arabic, Chinese, Japanese, Korean, Hindi, Indonesian, Russian, Hebrew, and Vietnamese.
- Can Just Converter convert HEIC to JPG without uploading the file?
- Yes. Just Converter converts HEIC images (from iPhone and iPad) to JPG, PNG, WEBP, and other formats entirely on your Windows device. The file never leaves your computer. There are no file size limits, no upload wait times, and no account required.
- How is Just Converter different from online converters like CloudConvert or SmallPDF?
- Online converters require you to upload your files to a server, which introduces privacy concerns, file size limits, and upload/download wait times. Just Converter processes every file locally on your own machine using FFmpeg and libvips. There are no size limits (only your hardware), no cloud dependency, no account, and your files stay on your device at all times.
- Does Just Converter support converting video to animated GIF?
- Yes. Just Converter can export video files as animated GIF. Select any supported video input (MP4, AVI, MKV, MOV, WMV, WEBM), choose GIF as the output format, and the entire conversion runs locally without any upload.
