AVI to MP4 Converter
Bring old AVI videos from cameras, DVDs and downloads back to life as MP4 files that play on every device.
- No upload
- No file size cap
- No credits or watermark
- Batch convert
Drop files here to convert to MP4
AVI, WMV, FLV and other videos. Files are converted on this device and never leave it.
What is an AVI to MP4 converter?
AVI is a Microsoft video container from the 1990s, used by older digital cameras, DivX and Xvid files and many archives. Modern phones, TVs and editors often cannot play the codecs inside AVI files. This converter decodes the AVI in your browser with the FFmpeg engine and re-encodes it to H.264 video and AAC audio in an MP4, the most compatible combination available.
How to use AVI to MP4 Converter
- Choose Open File or drop your AVI files.
- Optionally limit the resolution or trim the clip.
- Select Convert to MP4. The first conversion downloads the 32 MB compatibility engine, which is then cached.
- Preview and download the MP4, or a ZIP of several.
Why convert MKV to MP4 here
- No upload, no size capFamily videos and archives are read straight from your disk and converted on your device. Nothing is queued on a server or counted against a quota.
- Handles DivX, Xvid and MJPEGOld camera and download codecs are decoded with FFmpeg and re-encoded to H.264.
- Plays everywhereH.264 + AAC in MP4 works on iPhone, Android, smart TVs, Windows, Mac and the web.
- Batch convert with ZIPAdd several files, convert them in one go with the same settings and download a single ZIP.
When you need MKV as MP4
- Old camera videos. MJPEG AVIs from 2000s digital cameras.
- DivX and Xvid files. Films and clips that will not play on modern devices.
- Video editing. Import into iMovie, Premiere or CapCut.
- Sharing. Send family videos to phones and messaging apps.
AVI conversion tips
- AVI files almost always need re-encoding, so conversion takes longer than a remux.
- Limit the resolution to 720p for faster conversion of large files.
- Odd frame sizes are rounded to even numbers, as H.264 requires.
- Keep the original AVI until you have checked the MP4.
Local conversion vs upload-based converters
| Feature | Digital ToolPad | Typical upload converter |
|---|---|---|
| Where the file is converted | On your device, in the browser | On the service’s servers after upload |
| File size | No cap set by us; limited by your device | Free plans are often capped (commonly around 1 GB or less) |
| Daily limits | None | Some services ration free conversions or use credits |
| Account or watermark | Never | Varies; some require sign-up for large files |
| MOV to MP4 without re-encoding | Automatic for H.264 videos | Varies |
| Works offline after loading | Yes, for the fast engine | No |
Upload services are useful when a device is too slow or a format is very unusual. For everyday conversions, keeping the file local is faster to start and keeps private recordings private. Looking for more? See all video and audio tools, convert screen recordings with WebM to MP4, or split a photo for Instagram with the grid maker.
Example: a 2008 camera clip
A 640 × 480 MJPEG AVI (350 MB for 3 minutes) becomes an H.264 MP4 of about 25 MB that plays on any phone.
What to expect from the result
AVI conversion uses the FFmpeg engine in WebAssembly, which is slower than hardware encoding: expect roughly real-time for SD video on a laptop. Files above about 2 GB may exceed browser memory in the FFmpeg engine.
AVI to MP4 Converter questions
How do I convert AVI to MP4 for free?
Open the AVI file, select Convert to MP4 and download the result. There is no sign-up, watermark or size limit.
Is this AVI to MP4 converter free and private?
Yes. It is free, with no account, watermark, daily credit or conversion count. Your file is opened by your browser and converted on your device; it is not sent to a conversion server. Closing the tab discards the working copy. Downloaded results stay on your device.
Why does AVI conversion take longer than MKV or MOV?
AVI codecs such as DivX, Xvid and MJPEG are not compatible with MP4, so the video must be re-encoded rather than copied.
Will the MP4 be smaller?
Usually yes. H.264 is far more efficient than older AVI codecs, so files often shrink to a fraction of the size.
Is there a file size limit?
We do not set one. The fast engine reads your file in small pieces, so multi-gigabyte videos work on most desktops. The practical limit is your device memory. In Chrome and Edge you can save a single large MP4 directly to disk while it converts. The FFmpeg fallback, used only for unusual codecs, works best below about 2 GB.