AVI to MP4 Converter – Free, Fast & Private
Convert legacy AVI files to modern MP4 locally in your browser — your video never leaves your device
How to convert AVI to MP4
Choose or drag in your AVI file — nothing is uploaded, it stays on your device.
Click Start Converting — H.264 sources are rewrapped losslessly in seconds; other codecs are re-encoded to MP4 (H.264/AAC).
Download your standard MP4 file.
About AVI to MP4 conversion
AVI is a 1990s container that modern phones, browsers and web platforms handle poorly. This tool re-encodes your AVI into a standard H.264 MP4 that plays everywhere — entirely in your browser, with nothing uploaded.
Frequently asked questions
AVI files usually hold older codecs (DivX, Xvid, MJPEG…), so they are re-encoded to H.264 at a bitrate chosen to preserve the source's visual quality. For typical AVI sources the result looks the same while often being smaller.
The common ones: MPEG-4/DivX/Xvid, MJPEG, MPEG-1/2, WMV/VC-1, DV and raw video, plus MP3/PCM audio. If a codec isn't recognized you'll get a clear error instead of a broken file.
No. The conversion runs entirely in your browser using WebAssembly (FFmpeg). Your file never leaves your device — that is also why there is no upload wait, no queue and no file-size pricing.
Up to 8GB on desktop browsers and 2GB on mobile. There is no limit on the number of files you convert, and no signup or watermark.
Yes — completely free and unlimited, with no watermark, no signup and no daily quota. Because the conversion runs on your own device instead of our servers, there are no processing costs to charge for.
If the source already contains H.264 video, the file is rewrapped without re-encoding and finishes in seconds, even for gigabyte files. Other codecs are re-encoded in parallel WebAssembly workers, which runs at roughly real-time speed on a modern computer.
Yes. It runs in any modern browser — Chrome, Safari, Edge or Firefox — on Windows, macOS, ChromeOS, Linux, iOS and Android. There is nothing to install.
AAC and MP3 audio is copied over unchanged. Other audio codecs (PCM from cameras, Vorbis, Opus…) are converted to AAC so the resulting MP4 plays everywhere.