Convert AVI to MP4 Online

Upload an AVI file and convert it to MP4 for universal playback. Works on every device and browser, no software needed.

How it works

  1. Upload your AVI file. Drag your AVI video into DomeScribe. Legacy AVI files using DivX, Xvid, MPEG-4, or uncompressed codecs are all handled automatically.
  2. Analyze the legacy container. DomeScribe scans the AVI file and reports its video codec, audio codec, resolution, and frame rate. This analysis ensures the best encoding strategy is applied during conversion.
  3. Set modern MP4 parameters. Choose H.264 or H.265 encoding with AAC audio for a modern, efficient MP4. You can also adjust resolution — for example, upscaling old 480p footage to a cleaner presentation or keeping the original dimensions.
  4. Modernize and download. Click Convert to bring your AVI into the modern MP4 format. The resulting file is dramatically smaller than the AVI source, streams efficiently over the web, and works on every current device.

Converter at a glance

Video formats
MP4, WebM, MOV, AVI, MKV
Audio formats
MP3, WAV, FLAC, M4A, OGG, AAC
Privacy
Runs 100% in your browser (WebAssembly) — your file is never uploaded to a server
Speed
No upload or download wait — conversion starts instantly, even for large files
Watermark
None, ever
Free tier
10 conversions per month

Frequently asked questions

Why are AVI files so much larger than MP4?

AVI is a legacy container from the 1990s that often uses older, less efficient codecs like DivX or raw MPEG-4. MP4 with modern H.264 or H.265 encoding achieves the same visual quality at a fraction of the file size thanks to decades of compression improvements — the encoding DomeScribe uses when converting.

Can DomeScribe handle very old AVI files with unusual codecs?

Yes. DomeScribe includes broad codec support for legacy AVI files, including DivX, Xvid, Cinepak, Indeo, MJPEG, and uncompressed AVI. If the file plays on your computer, DomeScribe can almost certainly convert it.

Will converting my AVI to MP4 improve the video quality?

A DomeScribe conversion will not add detail that is not in the original, but modern encoding can actually look cleaner at the same bitrate by reducing compression artifacts common in older codecs. The primary benefit is a much smaller file that plays everywhere.

I have old home videos in AVI format — is this a good way to preserve them?

Converting to MP4 is an excellent preservation strategy. AVI support is declining in modern software and devices, while MP4 will remain the dominant format for years. Converting now with DomeScribe ensures your home videos stay accessible on future devices and platforms.

How long does AVI to MP4 conversion take?

Since full transcoding is always required for AVI files, processing time depends on the video length and resolution. A typical 1-hour standard-definition AVI converts in a few minutes. HD AVI files take longer but DomeScribe optimizes the encoding pipeline for speed.

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