Convert AVI to MP4
To convert an AVI to MP4, drop the .avi into the converter above and click Convert to MP4; the file downloads when it is ready. Re-encoding the video is more than a browser can do for a large file, so it is sent to our server over an encrypted connection, converted, and then deleted. The output is a standard MP4 (H.264 video, AAC audio) that modern devices play and that is usually smaller than the original.
Encrypted upload on an EU server, deleted within about an hour.
Drop your AVI hereChoose a AVI to convert
It becomes a MP4 right in your browser, up to 500 MB
Limits, published exactly
| Where it runs | On our server, over an encrypted connection; deleted within about an hour. |
|---|---|
| Free conversions | 2 per day without an account, 5 per day with a free account. |
| Max file size, free | 500 MB |
Why convert AVI to MP4?
AVI is an old Microsoft container from the 1990s. Plenty of archived and camcorder footage still lives in it, but it is a poor fit for modern life: the files are large, mobile and web support is spotty, and many editors and players struggle with the older codecs inside. Converting to MP4 with H.264 brings the clip up to date so it plays on a phone, uploads to the web, and drops into a modern editor without a fight.
What is AVI?
AVI (Audio Video Interleave) is Microsoft's 1992 video container, the format of camcorder archives, old screen recordings and a fair chunk of every family's digital history. The container predates modern streaming: no proper support for modern codecs' features, gigantic files, and shrinking support in current players and phones. Converting AVI to MP4 is the standard rescue for footage you want to keep watchable.
What is MP4?
MP4 is the default container of modern video: phones record into it, cameras export it, and every browser, TV and editing tool plays it, usually carrying H.264 video and AAC audio. Being a container, an MP4 is really a box around separate video and audio tracks, which is why useful conversions include not just other video formats but also pulling the audio track out on its own.
Quality and what to expect
The video is re-encoded to H.264 and the audio to AAC. Because AVI often holds a dated, lightly compressed codec, the modern H.264 output is frequently smaller than the source as well as far more compatible. This is a re-encode, not a lossless copy, so there is a small generational quality step at the high-quality default. Dimensions are preserved (evened for H.264, which matters because old AVI files sometimes have odd widths), with fast-start enabled. On privacy, this is a server conversion: the upload is encrypted, the input is deleted immediately after conversion and the MP4 within about an hour, and the dropzone marks it a server conversion before you start.
AVI to MP4 FAQ
Why convert AVI to MP4 at all?
AVI is a 1990s container: large, with dated codecs and patchy support on phones, browsers and modern editors. MP4 with H.264 is smaller, plays everywhere, and edits cleanly, so converting modernizes the clip without you re-shooting anything.
Will the file get smaller?
Usually, yes. AVI often stores video in an older, lightly compressed codec, so re-encoding to H.264 typically shrinks the file while keeping it visually close to the original.
Will the video lose quality?
A small, usually imperceptible amount, since it is re-encoded to H.264 at a high-quality setting rather than copied bit for bit. For dated AVI footage the compatibility and size gains almost always outweigh it.
Is my video uploaded to a server?
Yes. Re-encoding a large video cannot run in a browser, so the AVI uploads over an encrypted connection, converts, and is deleted: the input immediately after conversion, the MP4 within about an hour. The dropzone labels it a server conversion before you start.