How to convert AVI to MP4
Converting AVI to MP4 takes three quick steps:
- Add one or more AVI files — drag and drop them or click to browse.
- Click Convert to MP4 and let the conversion run in your browser.
- Download your new MP4 files individually or as a batch.
What is AVI?
AVI is an older Microsoft video format from the 1990s. It is widely recognised but inefficient by modern standards, producing large files, so it is usually converted to MP4 for sharing and storage.
What is MP4?
MP4 is the most widely compatible video format in the world. Using efficient H.264 compression, it balances small file sizes with good quality and plays on virtually every device, browser and platform — making it the safe default for sharing video.
AVI vs MP4: how they compare
Both formats have their place. This table summarises the practical differences so you can pick the right one for the job.
| AVI | MP4 | |
|---|---|---|
| Format type | Video | Video |
| Compression | Varies (often lightly compressed) | Lossy (H.264/H.265) |
| Quality | Lossy | Lossy |
| Best for | Legacy video archives | Sharing video anywhere |
Why convert AVI to MP4?
Converting AVI to MP4 gives you a file that is better suited to sharing video anywhere and web and social media, and that opens it up to far more apps, devices and websites.
What MP4 gives you: plays on virtually every device, good quality-to-size ratio and universal browser support.
Where AVI falls short: large files, outdated and limited streaming and mobile support. Converting keeps your content while moving to a format that matches where the file is going.
Tips for the best results
- You can convert several files in one go — add as many AVI files as you like and download them together.
- Everything runs locally in your browser, so even large files convert quickly and nothing is uploaded.
AVI to MP4 — frequently asked questions
- How do I convert AVI to MP4?
- Add your AVI file, click Convert to MP4, and download the MP4 result. The whole process happens in your browser and takes just a few seconds.
- Is it free to convert AVI to MP4?
- Yes. This AVI to MP4 converter is completely free with no sign-up, no watermarks and no limit on the number of files you can convert.
- Are my AVI files uploaded to a server?
- No. Conversion runs entirely on your device using your browser, so your files never leave your computer or phone.
- Will I lose quality converting AVI to MP4?
- MP4 uses lossy compression, so a small amount of detail is discarded to keep the file size down. At normal quality settings the difference is hard to notice. Keep your original AVI if you need an exact copy.
- Can I convert multiple AVI files at once?
- Yes. Add as many AVI files as you like and convert them in a single batch, then download each MP4 result.