Convert AVI to MP4

Turn AVI videos into MP4 files for the apps and sites that ask for MP4. The video is copied into the MP4 instead of re-encoded, so quality stays exactly the same and it takes seconds. AVIs with H.264 video play everywhere afterwards; older Xvid and DivX videos are copied too, but play only in VLC and on Windows until they're re-encoded. It runs in your browser, so your videos are never uploaded.

Drop AVI videos hereChoose AVI videos

They become MP4 files right on your device.

Choose files

Your files stay on this device. Nothing is uploaded.

SoundAAC and MP3 are always copied. Opus, FLAC, AC-3 and E-AC-3 don't play in every player.

How to convert AVI to MP4

Add your AVI videos
Drop one or more AVI files on the blue box on this page, or choose them from your device.
Wait a few seconds
Each video is rewrapped into MP4 on your device. Even large files take seconds, because the picture is copied rather than re-encoded.
Download the MP4
Play the result on the page, then download it. Each file's row says what was copied, what was converted and where it plays.

AVI to MP4: details

Input: AVI
Output: .mp4 with the original video stream
Quality: Unchanged; the video is copied, not re-encoded
Video: H.264 is copied and plays everywhere; Xvid and DivX, also with B-frames, are copied in the right order but play only in apps like VLC; H.264 with B-frames, DivX 3, Motion JPEG and older codecs need re-encoding
Audio: Kept as it is when an MP4 can hold it (AAC, MP3, Opus, FLAC, AC-3, E-AC-3); DTS, Vorbis, PCM and others become AAC. Convert to AAC makes sound that plays everywhere
Tracks: The main video and the default audio track; subtitles and extra audio tracks are left out
Metadata: The recording date is kept; the location (GPS) is left out
Upload: None; videos are converted in your browser
Several files: Yes, add as many as you like
Price: Free

AVI to MP4: questions

How do I convert AVI to MP4?

Rewrap the video instead of re-encoding it. On tuul.io you add your AVI files and download the MP4s: the video is copied over as it is, so quality stays the same and even a large file takes seconds rather than minutes.

Will the MP4 play on my phone?

If the AVI holds H.264 video, yes. Most older AVI files hold Xvid or DivX (MPEG-4 Part 2) video. The MP4 keeps it, so it plays in VLC and on Windows, but not in browsers or on most phones. Making it play there needs re-encoding to H.264, which this tool doesn't do.

Why can't some AVI files be converted?

DivX 3, Cinepak, Indeo and uncompressed video can't go into an MP4 without re-encoding, and Motion JPEG can, but nothing plays it from there. H.264 with B-frames can't be copied either, because AVI doesn't record the order to show them in. Xvid and DivX with B-frames are put back in order and copied. The file's row says which case applies.

Does converting AVI to MP4 lose quality?

No. The video stream is copied into the MP4 without re-encoding, so every frame stays the same. MP3 and AAC audio are copied too; other audio is converted to AAC.

Are my videos uploaded?

No. The converter downloads once to your browser and then runs on your device, so your videos never leave it.

Can I convert several videos at once?

Yes. Add as many as you like; they are converted one after another and each gets its own download button.

Does it work on a phone?

Yes, in current versions of Safari and Chrome. Very large files can run out of memory on phones, so for videos over about 1 GB a computer is more reliable.

Next steps

Video trimmerCut the part you need out of a video or CCTV recording, without re-encoding it.
Video to MP3Take the sound out of any video, CCTV too, as MP3.