About AVI to MP4 conversion

AVI (Audio Video Interleave) is a legacy video container format from Microsoft dating back to 1992. AVI files are often large, use outdated codecs, and are not supported by modern mobile devices or streaming platforms. Converting to MP4 dramatically reduces file size while greatly improving compatibility.

This converter re-encodes using H.264 video and AAC audio — the modern standard for MP4. Processing is done entirely in your browser via FFmpeg.wasm; your video file is never uploaded to any server.

Frequently Asked Questions

Why convert AVI to MP4?

AVI files use old codecs (DivX, Xvid, etc.) that are not supported by modern devices. MP4 with H.264 works on iPhones, Android phones, smart TVs, social media, and virtually everything else.

Will the file size get smaller?

Usually yes — significantly. AVI files are often much larger than equivalent MP4 files because H.264 compression is far more efficient than older codecs like Xvid or DivX.

Can I upload the result to YouTube or social media?

Yes. MP4 with H.264 is the recommended format for virtually all video platforms.

Is my file kept private?

Yes. The entire conversion runs in your browser — nothing is uploaded to any server.

What browsers are supported?

Chrome and Edge work reliably. Recent Firefox versions also work. Safari support depends on the version.