AVI to MP4 Converter

An avi to mp4 converter is a utility that changes legacy Audio Video Interleave files into modern MP4 containers using standard video codecs like H.264. OnVid provides a free browser tool that re-encodes the video to H.264 locally without sending your private media to an external server.

OnVid's version processes video directly on your device using WebAssembly and client-side FFmpeg libraries. The browser downloads the small processing engine once, inspects your video stream, and re-encodes it into an H.264 MP4 without uploading raw media files to the cloud.

Yes. The tool is free, needs no sign-up and runs in your browser. There is no account, no daily limit on conversions and no watermark; each file can be up to 400 MB.

To convert avi to mp4, open the converter tool, drag your file into the browser window, and click Convert to MP4. The tool processes the video locally, then shows a preview and a download button for the clean MP4 file.

Converting avi to mp4 free on OnVid leaves your original video untouched and adds no watermark. The browser tool runs purely as a file utility, delivering clean MP4 files ready for sharing or editing.

When you turn an avi file to mp4, the video is re-encoded to H.264 with AAC audio and saved in an MP4 container supported by modern operating systems, web players and mobile devices, most of which have built-in H.264 decoding.

Convert them to MP4 first, which often makes old AVI files smaller on its own. If the file is still too big, run it through OnVid's separate Video Compressor, which can also cap the resolution at 1080p, 720p or 480p.

Yes. The tool runs in modern mobile browsers that support WebAssembly, the processing happens on your phone and no watermark is added. Phones re-encode more slowly than computers, so large files take longer.

Apple devices do not natively decode AVI containers in the Photos app or Safari browser. Converting an avi to mp4 iphone format ensures your video plays natively across iOS, iPadOS, and macOS without extra third-party media players.

Converting to MP4 re-encodes the video to H.264, which on its own often shrinks old AVI files. For more control, run the MP4 through OnVid's separate Video Compressor: it offers light, balanced or strong compression and can cap the size at 1080p, 720p or 480p.

The browser converter supports source files up to 400 MB. Because processing runs entirely within client memory, this cap ensures your browser tab remains stable and responsive throughout the encoding process.

AVI files usually hold older codecs such as DivX, Xvid or MJPEG, so the tool re-encodes the video to H.264 (CRF 23) with AAC audio. That setting keeps the picture visually close to the original at the same resolution, but a re-encode is never lossless, so keep your original AVI as a master copy.

Yes, once your MP4 is ready, you can upload clips under 30 seconds into OnVid's AI video generator on a Pro or Max plan. The video-to-video workflow lets you remix visuals or integrate new characters using models like Seedance 2.5.

No. The MP4 gets the first video track and the first audio track only, with the audio saved as AAC. Any extra audio tracks or subtitle streams in the AVI are not carried over, so keep the original file if you need them.

No. The file is read and converted inside your browser tab and is never uploaded, so OnVid never receives or keeps a copy. The converted result stays in the tab until you download it, and closing the tab clears it, so save the file before you leave the page.

The free browser tool does not use AI and has no cloud processing or batch mode. Files are capped at 400 MB, the output is always H.264 MP4 with AAC audio, and there are no resolution, quality, trimming or editing options.