Convert AVI files to MP4 instantly and privately. File Converts runs entirely in your browser, so your AVI is never uploaded to any server.
No upload Instant Free
Runs in your browser via WebAssembly — your media is never uploaded. The FFmpeg engine (~30MB) downloads once on first use, so the first conversion takes a little longer.
Works offline after you have used it once: the engine downloads the first time and is kept. About 30 MB, once.
Privacy, proven — live
Online
0 BUploaded to our servers
0Requests carrying your data
0Files stored by us
—Processed on your devicedrop a file
Conversions run entirely in your browser. Turn off your Wi-Fi and try it — it still works. Nothing leaves this device.
AVI dates from 1992 and shows it. The container has no modern feature set, produces larger files than it needs to, and typically holds older codecs — DivX, Xvid, MPEG-4 Part 2 — that modern phones and browsers may not decode even when they open the file.
That makes this conversion different from the other container changes here. Where a MOV usually remuxes untouched, an AVI holding a legacy codec needs a genuine re-encode to H.264, which takes longer and is lossy. It is still worth doing: the result is smaller, plays everywhere, and the source was already a compressed copy of something older.
AVI files usually come from old camcorders, ripped discs and archived downloads, which is to say footage you may not have another copy of. Converting in your browser means the original never leaves your machine, and the file you started with is untouched on disk.
How to convert AVI → MP4
01
Drop your AVI file into the converter above — it stays on your device.
02
Choose MP4 as the output. File Converts picks the smartest settings automatically.
03
Click Convert and download your MP4 file instantly.
Frequently asked questions
AVI is an older video container with broad legacy support but larger files. MP4 is the most widely supported video container — it plays virtually everywhere. Converting AVI to MP4 keeps your content while giving you MP4's strengths.
Yes — it's completely free with no sign-up and no limits, because the conversion runs on your own device.
No. File Converts converts your AVI to MP4 entirely in your browser. Your file never leaves your device, which makes it both private and instant.
Yes. We use high-fidelity rendering and let you control output quality where it applies, so your MP4 stays crisp.
Yes. The converter is mobile-first and works in any modern browser on phone, tablet, or desktop — and offline once its engine has downloaded on your first use.
