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.
Drag and drop your video here
or
Choose videoMP4, MOV, AVI, MKV, WebM and more · up to 500MB per file · select several to batch compress
camcorder-2009.avi
Ready to download
72 MB
from 690 MB
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Typically the largest size reduction of any format, since AVI often uses outdated or uncompressed codecs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.
Recommended settings
What we'd pick for this job. After choosing a file, resolution sits right under the compression settings, crop is under “Resize / crop”, and codec is under “Advanced settings”.
By quality · Basic
Older footage is often low-res already — keep what detail it has.
H.264
Modern, universally supported replacement for DivX/Xvid.
Original
Old footage is usually 480p or lower already — don't shrink it further. Caps above the video's size switch off by themselves.
Original
Preserves the 4:3 framing of older recordings.
Your archived original
Compress a copy and keep the AVI as your master.
Tips for the best result
Old codecs, big savings
AVI files often hold DivX, Xvid, MJPEG, or even uncompressed video. Re-encoding to modern H.264 in an MP4 routinely cuts the size by 80–90% at similar quality.
Keep your archive copy
Digitised home videos are irreplaceable. Compress a copy for sharing and keep the original AVI in storage — you can always make another copy later, but not a better one.
Check audio after converting
Some AVIs use unusual audio codecs. Play the first few seconds of the result to confirm the sound came through before deleting anything.
Trim before you compress
Every second you cut is size saved at full quality. Removing a slow intro or a long ending is usually worth more than an extra compression step.
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.