Compress AVI Video Online
AVI is an older Windows container format that's often stored with little to no compression, resulting in very large files.
Drop your video here
or browse your files
Processed on your device — nothing is uploaded
Modernizes an old, inefficient container into H.264/MP4
Typically the largest size reduction of any format, since AVI often uses outdated or uncompressed codecs
Improves compatibility — many modern devices and apps have dropped native AVI support
Why compress AVI files?
Converting and compressing AVI to MP4 can reduce file size dramatically since AVI rarely uses modern, efficient codecs.
How it works
Step 1
Upload
Drop your file in — up to 500MB free.
Step 2
Pick a quality
Basic, Strong, or Superb compression.
Step 3
Download
Get your smaller video in seconds.
Frequently Asked Questions
AVI is an older container format from the 1990s that's often paired with less efficient codecs (or none at all), so it doesn't compress video nearly as well as modern H.264/MP4.
Many mobile devices and streaming apps dropped native AVI support, which is one of the main reasons people convert AVI files to MP4 in the first place.
Re-encoding often resolves minor sync drift found in old AVI files, since the audio and video are re-muxed together from scratch during compression.
It varies by source, but AVI files frequently shrink by 70–90% when re-encoded to compressed MP4, since the original is often stored with minimal compression.
Yes, the underlying engine can read most common AVI codecs (DivX, Xvid, MJPEG) and re-encode them into a standard H.264 MP4.