Updated June 2026 · runs 100% in your browser
AVI to MP4
Convert legacy AVI videos to MP4 on your device. No upload, no sign-up, no limits.
Drop AVI files here
or click to choose
🔒 Processed on your device · 0 bytes uploaded
First file loads the converter engine (~25 MB) — cached after that.
How it works
ConvertCabin loads a local copy of FFmpeg in this browser tab and converts on your device — nothing is uploaded. The first file downloads the engine (~25 MB), then it's cached.
It stays free, unlimited and private, and works offline once loaded.
About AVI to MP4
AVI is an older container; MP4 is smaller and far more compatible.
Frequently asked questions
How do I use AVI to MP4?
Drop AVI files and download the MP4s.
Is my file uploaded?
No. It is converted on your device by a local copy of FFmpeg and never uploaded.
What is an AVI file?
AVI is an older Microsoft video container. It's widely playable but produces large files and lacks modern features, so it's commonly converted to MP4.
What is an MP4 file?
MP4 is the most universally compatible video container. It typically holds H.264 video with AAC audio, plays on virtually every device, and balances good quality with reasonable file size.