AVI to MP4 Converter - Convert AVI to MP4 Online Free

How to convert AVI to MP4

Add your AVI videos. Drop up to 20 AVI files into the box, or browse for them. Each one can be up to 200 MB.
Pick a preset. Match source keeps the picture as it is, Web 720p and Small file make the MP4 easier to share.
Trim if you like. Set the start and end in the Trim row to keep only the part you need.
Convert and download. Press Convert. One or two files download directly, more than two come as a ZIP with a README.

Found a funny moment in an old clip? Turn it into a GIF with Video to GIF.

What is an AVI file?

AVI is Microsoft's video format from 1992.

It was the standard for DivX and Xvid movies and for clips from digital cameras and early phones.

Today phones, smart TVs, browsers and most upload forms no longer open it. MP4 with H.264 plays everywhere, so converting keeps those memories watchable.

Which AVI codecs are supported?

AVI is only a container - the codec inside decides how old the file really is. All of these become H.264 video with AAC sound:

DivX and Xvid (MPEG-4 Part 2) - the classic movie and TV rips of the 2000s.
Motion JPEG - what Canon, Nikon, Sony and Kodak compact cameras recorded. Every frame is a full JPEG, so these files are huge and shrink a lot.
DV, Cinepak, Indeo and others - anything FFmpeg can decode.
H.264 in AVI - the video is copied as it is, only the sound is converted.

Sound in MP3, PCM or ADPCM becomes AAC, the audio format every device understands.

AVI vs MP4

	AVI	MP4
Introduced	1992 (Microsoft)	2001 (MPEG, ISO standard)
Typical codecs	DivX, Xvid, MJPEG + MP3, PCM	H.264 + AAC
File size	Large, MJPEG very large	Small for the same quality
Streaming	Must download fully first	Starts playing right away
Plays on	Windows PCs, VLC	Everything, including phones, TVs and browsers

Got Flash videos as well? FLV to MP4 handles those.

Tips

Camera clip is 640 x 480? Keep Original - enlarging adds no detail, and the MP4 is never upscaled anyway.
Odd size like 352 x 241? H.264 needs even dimensions, so the size is nudged by one pixel where needed.
Interlaced lines on old TV captures? Those stay as they are - this page does not deinterlace.
Only want the sound? Video to MP3 takes AVI files too.

Your video is converted on our server with FFmpeg. The upload is deleted right after converting and the MP4 once you download it.

Frequently Asked Questions

Drop your AVI into the box, keep the Match source preset and press Convert.

One or two files download directly, more than two come as a ZIP.

Usually yes. H.264 is far more efficient than DivX or Xvid, and Motion JPEG camera clips often shrink to a tenth of their size. The real size is shown after converting.

The video is re-encoded, but with Match source at CRF 20, which looks the same as the original. An AVI that already holds H.264 has its video copied without any change.

Yes. DivX and Xvid are MPEG-4 Part 2 codecs and convert to H.264 MP4 without any extra codec packs.

Most camera AVIs use Motion JPEG with PCM sound, which modern phones and TVs ignore. Converting to H.264 MP4 makes them play again. Badly damaged files may still fail - then we show a clear message.

Windows needs a codec for what is inside the AVI, and DivX, Xvid or older camera codecs are no longer included. An H.264 MP4 plays in the built-in Media Player.

Up to 200 MB per video and 20 videos per batch. For longer videos, trim the part you need or pick 720p.

Yes, it is free with no account. Your video travels to our server over HTTPS, is deleted as soon as the MP4 is made, and the MP4 is deleted once you download it.