AVI to MPEG4 Converter
Processing entirely on your device — large files may take a moment.
Convert MPEG4 files exactly like MPG — to MP4/H.264. If your files are still in AVI format, this page is the shortcut: AVI is Microsoft’s classic video container from the 90s. Files are large by modern standards but old devices and software still produce them.
This converter runs entirely in your browser using WebAssembly — your files never leave your device, nothing is uploaded, and there are no watermarks, sign-ups or queues. Drop in several files at once to convert them as a batch.
How AVI compares to MPEG4
| AVI | MPEG4 | |
|---|---|---|
| Compression | Legacy codecs (DivX/Xvid era) | MPEG-1 / MPEG-2 |
| Quality | Capped by its era | Standard definition |
| Compatibility | Legacy Windows tooling | Universal decode |
| Best for | Reading old archives | Legacy disc and capture video |
How to convert AVI to MPEG4
- 1
Select your files
Drag & drop your AVI files onto the area above, or click to browse. You can add multiple files at once for batch conversion.
- 2
Convert instantly
Click "Convert to MPEG4". The conversion runs entirely inside your browser using WebAssembly — no upload, no queue, no waiting.
- 3
Download results
Download each converted MPEG4 file individually, or grab everything at once as a ZIP archive.
About the AVI format
AVI (Microsoft, 1992) is one of the oldest video containers still encountered. It has no native understanding of modern features — variable frame rates, modern codecs, subtitles, chapters — and stores everything through a 32-bit indexing system that caps reliable file sizes around 2 GB (OpenDML extensions patched some of this). Most AVIs you meet today are DivX/Xvid-era rips or old capture-card output.
There is no reason to produce AVI today; the realistic task is converting old libraries into MP4, which typically cuts file size by half or more at equal or better quality.
+Strengths
- ✓Opens in legacy Windows tooling
- ✓Simple structure, decades of player support
!Limitations
- −Obsolete: no modern codecs or features by design
- −Large overhead, ~2 GB practical ceiling
- −Codec zoo inside — playback is guesswork
About the MPEG4 format
MPG (MPEG program stream) usually means MPEG-1 or MPEG-2 video — the codecs of VCD, SVCD and DVD, and of countless home video captures in the 1990s and 2000s. MPEG-1 tops out around VHS-grade 352×288; MPEG-2 delivers proper standard definition and still runs inside broadcast and DVD infrastructure.
Playback compatibility is its superpower: MPEG-1/2 decode paths exist in every player and hardware made this century. Quality-to-bitrate efficiency, however, is a generation behind H.264 — converting old MPG files to MP4 typically halves their size.
+Strengths
- ✓Decodes on essentially every player and device
- ✓Simple, battle-tested standard
!Limitations
- −Inefficient codecs by modern standards
- −MPEG-1 is VHS-grade at best
Why convert AVI to MPEG4?
Converting makes sense where the strengths of MPEG4 meet what AVI cannot give you. Decodes on essentially every player and device Meanwhile Obsolete: no modern codecs or features by design One pass through the converter above puts your file on the right side of that trade-off.
Frequently asked questions
Is this AVI to MPEG4 converter really free?
Yes — completely free, with no sign-up, no watermark and no daily conversion limits. The site is supported by advertising.
Are my files uploaded to a server?
No. The conversion runs entirely inside your browser using WebAssembly, so your files never leave your device — that is what makes it instant and private.
Does it work on Windows, Mac, iPhone and Android?
Yes. Anything with a modern browser works: Windows, macOS, Linux, Android and iOS. No software installation is required.
Is there a file size limit for AVI to MPEG4?
The only limit is your device's memory, since nothing is uploaded. Files up to a few hundred megabytes work fine on a modern desktop browser; very large files simply take a little longer.
Why is video conversion slower than image conversion?
Every frame has to be decoded and re-encoded. This site runs that work on your own CPU via WebAssembly — nothing is uploaded, but a multi-minute video reasonably takes a few minutes. Images, by comparison, are single-frame jobs.
Does converting AVI to MPEG4 re-encode my video?
Yes. The video is decoded and re-encoded with the settings chosen by the quality slider, which is what allows the format and size to change. For an archival copy, keep higher quality; for sharing, lower quality gives a much smaller file.