Free tool

AVI to MP4, old videos that play again.

Turn AVI files from old cameras, phones and downloads, with Xvid, DivX, Motion JPEG or H.264 inside, into MP4 videos that play on a Mac, an iPhone, in a browser and on every site. It runs in your browser with a small FFmpeg made for this page, so the video is never uploaded. No sign-up, no watermark.

Drop an AVI video here, or click to choose Any .avi file. It stays on your computer.

This runs in your browser. Your videos are never uploaded.

How it works

Three steps, nothing to install.

01 / Drop

Choose the AVI

Its first picture shows, with the size, length and what is inside.

02 / Convert

Pick size and quality

Every frame is read and saved again as H.264, the sound as AAC.

03 / Save

Play and download

Check the MP4 right here, then download it.

Questions

Good to know.

Is my video uploaded?

No. It is read and converted in this tab, so it never leaves your computer. No account, no watermark, no length limit.

Why will an AVI not play on my Mac or phone?

AVI is an old container from Windows, and the video inside is often Xvid, DivX or Motion JPEG, which QuickTime, iPhones and browsers do not play. MP4 with H.264 plays almost everywhere.

Which AVI files work?

AVI files with Xvid, DivX (including DivX 3), H.264, Motion JPEG (many old digital cameras), MPEG-1 and 2, WMV 7 and 8, DV, Cinepak or Microsoft Video 1 pictures, and MP3, AC-3, AAC, PCM, ADPCM or WMA sound. A file with another codec says so when you drop it.

How does it read AVI in a browser?

With a small build of FFmpeg, the open video library, compiled to WebAssembly by libav.js. It has only the AVI reader and the decoders above, about 3 MB, and is licensed LGPL 2.1. The browser's own encoder then writes the H.264 MP4.

Does converting lower the quality?

Every frame is encoded again, so there is a small loss, as with any conversion. High keeps the most detail; Balanced is hard to tell apart from the original for most videos.

How long does it take?

Roughly as long as the video plays for a standard-definition file on a recent computer, longer for HD. The page shows the time left. Keep the tab open until it is done.

Which browsers work?

Current Chrome, Edge and Safari, which can encode H.264. Firefox can read the AVI but may not be able to write the MP4.