AVI file format (.avi)
Classic Windows container with MPEG-4 video.
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What is an AVI file?
In short: An AVI file (.avi) is a video file in the AVI format. AVI is a simple container from before modern video: it interleaves chunks of audio and video and does little else. It can be converted to MP4, MOV or GIF for free in a web browser with iHateFiles, without uploading it.
Introduced by Microsoft in 1992, and the standard on Windows for a decade.
AVI is a simple container from before modern video: it interleaves chunks of audio and video and does little else. It has no proper support for variable frame rates, modern subtitles or the metadata that newer containers take for granted, which is why it was replaced.
What AVI is good at
- Understood by very old software
- Simple structure, easy to repair
- Still common in archives and on older camcorders
Where AVI falls short
- No variable frame rate support, which causes drift
- Poor subtitle and metadata handling
- Files are noticeably larger than a modern equivalent
When to use AVI
Convert AVI to MP4. There is no reason to create a new one.
How to open a AVI file
Windows, VLC and most desktop players. Not browsers, not phones.
| Windows | Opens in Films & TV and VLC, though a 1990s AVI using an obsolete codec may play as sound with a black picture. |
|---|---|
| macOS | VLC or IINA. QuickTime dropped AVI support years ago. |
| Linux | VLC and mpv, with the caveat that very old codecs need the full FFmpeg codec set installed. |
| Phone | VLC. Most stock phone players ignore AVI entirely. |
| In a browser | No browser plays AVI. |
The thing that usually goes wrong
Audio drifting out of sync partway through an AVI is common, because the container assumes a fixed frame rate that the source did not actually have. Re-encoding to MP4 corrects the timing.
Questions
What is a AVI file?
Classic Windows container with MPEG-4 video. Files use the .avi extension.
How do I open a AVI file?
Most video software opens AVI directly. If yours does not, convert it here to something more common. It takes a few seconds and nothing is uploaded.
Can I convert AVI for free?
Yes. Every conversion here is free and unlimited, because your own device does the work rather than a server we have to pay for.
Is AVI lossless?
That depends on the codec inside the container rather than the container itself. Everything written here is re-encoded, so expect one generation of loss.