Convert AVI to MP4 Online
Swap FormatsConvert AVI to MP4 without uploading your files anywhere. This converter runs entirely in your browser — your files never leave your device. Free, instant, and 100% private. No account or software required.
Choose AVI files or drag & drop
Multiple files supported · No file size limit
Video Settings
How to Convert AVI to MP4 - 3 Simple Steps
Upload Your AVI File
Drag and drop your AVI file into the upload area above, or click to browse your device. You can upload multiple files at once for batch conversion.
Adjust Settings
Set your preferred quality, resize dimensions, or other format-specific options. The default settings are optimized for the best MP4 output.
Download MP4 File
Click Convert and your MP4 file is ready instantly. Download individual files or click "Download All as ZIP" for batch results.
AVI vs MP4 — Format Comparison
| Feature | AVI | MP4 |
|---|---|---|
| File Size | Large (legacy container) | Medium (H.264/H.265) |
| Compression | Lossy | Lossy |
| Transparency (Alpha) | ✗ Not supported | ✗ Not supported |
| Animation | ✓ Supported | ✓ Supported |
| Vector-based | ✗ No (raster) | ✗ No (raster) |
| Browser Support | Limited (older format, requires codecs) | All major browsers |
| Best For | Legacy Windows applications, older media players | Video sharing, streaming, social media, web playback |
Also Convert AVI to:
Convert Other Formats to MP4:
Convert AVI to MP4 Without Uploading — Why It Matters
Most online converters upload your files to remote servers for processing. ConvertTheFile is different — conversion happens 100% in your browser using modern web technologies. Your AVI files never leave your device.
Zero Upload
Your AVI files are processed locally. Nothing is sent to any server, ever. No cloud, no upload, no risk.
Complete Privacy
Perfect for sensitive documents, personal photos, and confidential files. We can't see your files because they never reach us.
Instant & Offline-Ready
No upload/download wait time. Conversion starts instantly. Works even with slow or no internet after the page loads.
Free, No Limits
No file size limits, no daily caps, no watermarks, no account required. Convert as many files as you need.
Batch Processing
Convert multiple AVI files to MP4 at once. Select all your files and process them in parallel.
Works on Any Device
Runs in Chrome, Firefox, Safari, and Edge on desktop and mobile. No software to install.
How Does AVI to MP4 Conversion Work Without Uploading?
Traditional file converters upload your AVI file to a remote server, process it, and send back the MP4 result. This means your file travels across the internet and sits on someone else's computer.
ConvertTheFile works differently. When you drop a AVI file into our converter, your browser reads the file locally and converts it to MP4 using built-in web technologies (Canvas API, WebAssembly, or JavaScript). The converted MP4 file is saved directly to your device. At no point does your file leave your computer.
This browser-based approach means zero privacy risk, faster conversions (no upload/download delay), and the ability to work offline after the page loads. It's the safest way to convert AVI to MP4 online.
Frequently Asked Questions — AVI to MP4 Converter
How do I convert AVI to MP4 online?
Is it safe to convert AVI files to MP4 online?
What is the difference between AVI and MP4?
Is this AVI to MP4 converter free?
Can I batch convert multiple AVI files to MP4?
How long does AVI to MP4 conversion take?
Does this converter upload my AVI files to a server?
Can I convert AVI to MP4 without uploading or installing software?
About AVI (Audio Video Interleave)
AVI is Microsoft's legacy container format supporting various codecs. While older, it remains common in Windows environments and older media players.
Learn more about AVI →About MP4 (MPEG-4 Part 14)
MP4 is the most universal video format, combining H.264/H.265 video with AAC audio. Supported by virtually every device, browser, and platform.
Learn more about MP4 →