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HomeVideoAVI to MP4

AVI to MP4 Converter

Convert AVI videos to compatible MP4 files. Free, private, runs in your browser.

100% private — your files and text never leave your browser. All processing happens locally on your device.

Choose a file

or drop it here

AVI·Up to 750MB

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Why AVI Files Often Need Help

AVI is an older container and often appears with legacy codecs from screen recorders, cameras, and old editing software. Modern browsers and phones prefer MP4 with H.264 video and AAC audio. This tool converts the container and, when needed, transcodes the streams into a more compatible MP4.

Choosing Auto, Remux, Or Transcode

Auto is the safest default. Remux is fastest when the AVI already contains MP4-compatible streams, but many AVI files do not. Transcode takes longer because it rewrites the video and audio, but it usually creates the most portable result.

Corrupt Or Legacy AVI Files

Some AVI files are incomplete or rely on codecs that the browser FFmpeg build cannot decode. When that happens, Convertful shows a local error instead of creating a broken download. Re-exporting the source from the original editor usually gives FFmpeg a cleaner input.

FAQ

Why convert AVI to MP4?

AVI is an older container and often depends on legacy codecs. MP4 with H.264/AAC is easier to play in browsers, phones, messaging apps, and modern editors.

Does AVI conversion use a server?

No. Convertful loads FFmpeg.wasm from the app and performs the conversion in your browser. Your AVI file is not uploaded for processing.

What if my AVI uses an old or corrupt codec?

The tool shows a local error if the browser FFmpeg build cannot decode the file. Try Transcode mode first; if it still fails, re-export the AVI from the original app.

Why does AVI usually need transcoding?

AVI files often contain older codecs that MP4 players do not support directly. Transcoding rewrites the video to H.264 and audio to AAC so the MP4 is more likely to play everywhere.

Can I cancel a slow AVI conversion?

Yes. Use the Cancel button while conversion is running. The in-browser FFmpeg worker is terminated and you can retry with a smaller file or a different mode.