How to Convert AVI to MP4 Online
Convert AVI to MP4 entirely in your browser — no upload, no software install. Your videos stay on your device while you get modern, universally compatible MP4 files that play on phones, tablets, smart TVs, and every major platform.
Universal Compatibility
MP4 plays on phones, tablets, computers, and smart TVs
Smaller File Size
MP4 uses modern compression for smaller files
Web Streaming
MP4 is the standard for web video streaming
Social Media Ready
Upload directly to YouTube, Instagram, TikTok
Modern Codec Support
H.264/H.265 codecs for excellent quality
Mobile Compatible
Works on all iOS and Android devices
| Feature | AVI | MP4 |
|---|---|---|
| Release Year | 1992 | 2001 |
| File Size | Larger | Smaller |
| Compression | Less efficient | Highly efficient |
| Browser Support | Limited | Universal |
| Mobile Support | Poor | Excellent |
| Streaming | Not optimized | Built for streaming |
Upload Your AVI File
Click upload or drag and drop your AVI video file. Our converter supports all AVI variants.
Select MP4 Output
Choose "MP4" as your output format. Optionally adjust quality and resolution settings.
Download Your MP4
Click convert and download your new MP4 file. Ready to play on any device!
AVI (Audio Video Interleave) was introduced by Microsoft in 1992 as the default container for early digital video. It served well for decades, but modern streaming, mobile playback, and web embedding have moved on. AVI lacks native support for efficient codecs, streaming metadata, and adaptive bitrate delivery that MP4 handles natively.
Most AVI files in personal archives come from older camcorders, DVD rips, screen recorders, and early torrent downloads. These files often use outdated codecs like DivX or Xvid that require separate codec packs on modern systems. Converting to MP4 with H.264 eliminates codec dependency — the result plays everywhere without installing anything.
If you also have QuickTime MOV files from iPhones or Macs, the same logic applies. Use our MOV to MP4 converter for Apple-format files, or the general video converter for batch jobs across formats.
A video file has two parts: the container (AVI, MP4, MKV) and the codec (the compression method for video and audio streams). Think of the container as an envelope and the codec as the language written inside. Changing from AVI to MP4 means repackaging your video into a modern envelope and often re-encoding the streams into widely supported formats.
H.264 (AVC): The safest choice for MP4 output. Plays on virtually every device made in the last 15 years — phones, smart TVs, browsers, game consoles. Use this for general sharing and archiving.
H.265 (HEVC): Produces smaller files at the same quality but has spotty support on older Android devices and some browsers. Choose H.265 only if you control the playback environment and need maximum compression.
Audio: Most AVI files use MP3 or AC3 audio, both of which convert cleanly to AAC — the standard audio codec inside MP4. Audio quality loss during conversion is negligible at default settings.
MP4 with H.264 video and AAC audio is the closest thing to a universal video standard. After converting from AVI, your files work on:
- iPhone, iPad, and Android phones (native gallery and messaging apps)
- Smart TVs (Samsung, LG, Roku, Apple TV, Fire TV)
- Web browsers (Chrome, Safari, Firefox, Edge) via HTML5 video
- Social platforms (YouTube, Instagram, TikTok, LinkedIn, Facebook)
- Video editors (DaVinci Resolve, Premiere Pro, iMovie, CapCut)
- Presentation software (PowerPoint, Google Slides, Keynote)
AVI files frequently fail on mobile devices and cannot be embedded in modern websites. One conversion pass saves repeated compatibility headaches when sharing family videos, training recordings, or archived footage.
Home videos, security camera footage, and personal recordings should not pass through cloud conversion services that store copies on remote servers. ConvertifyHub transcodes AVI to MP4 locally in your browser — your video bytes never leave your machine. This matches the approach on our no-upload converter page: no account, no queue, no retention policy.
Use the dedicated AVI to MP4 converter for single-format jobs, or batch through the video converter when you have mixed source formats.
Will converting AVI to MP4 reduce quality?
Re-encoding always introduces minor generational loss, but at default quality settings the difference is imperceptible on screen. If your AVI already uses H.264, some tools can repackage without re-encoding (remux) — browser converters typically re-encode for maximum compatibility.
Why won't my AVI file play on my phone?
Mobile operating systems prioritize MP4/H.264 and often lack codecs for DivX, Xvid, or WMV streams inside AVI containers. Converting to MP4 resolves this in one step.
How much smaller will the MP4 be?
Expect 30–60% size reduction when converting from uncompressed or lightly-compressed AVI to H.264 MP4. Already-compressed AVIs may see smaller savings. File size depends on source quality and chosen output settings.
Can I convert multiple AVI files at once?
Yes. Batch conversion is supported, though large files consume browser memory. Process in groups of 5–10 for best performance on typical laptops.
Should I delete the original AVI after converting?
Verify the MP4 plays correctly on your target devices first. Keep the AVI as a backup until you confirm quality and completeness, especially for irreplaceable home videos.