Convert AVI to MKV Online Free
AVI is a legacy Microsoft video container still found in older files and cameras. MKV is a flexible open container that can hold multiple video, audio, and subtitle tracks. FileConverter turns your AVI into MKV online in seconds - free, privacy-first, and with no software to install or account to create.
Convert AVI to MKV
MKV is already selected. Add your AVI file to start.
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Add a AVI file above to start the conversion.
AVI to MKV repackages legacy video into a flexible open container that can hold multiple audio and subtitle tracks.
What changes when you convert AVI to MKV
This re-encodes your footage from the AVI container into MKV, which can change the underlying codec and file size. At sensible settings quality is well preserved, but converting from a higher-quality AVI source always produces a better MKV result. Trim long clips first if you only need part of the footage.
About the AVI format
AVI is an older container that can hold high-quality, lightly compressed video, which is why files are often large. It plays on desktop players but is a poor choice for modern web and mobile delivery. In everyday use, AVI is chosen for older recordings and legacy archives and desktop playback of vintage footage. It opens in VLC, Windows Media Player, and most desktop players.
About the MKV format
Matroska is popular for high-quality films and archives because it can bundle many audio languages, subtitle tracks, and chapters in one file. It is great for storage but not natively supported by many phones or web players. In everyday use, MKV is chosen for high-quality film archives and multi-language and multi-subtitle collections. It opens in VLC and most desktop media players.
AVI vs MKV
AVI is best known for widely readable on Windows desktop players, while MKV stands out for stores multiple audio, video, and subtitle tracks. Choosing between them comes down to where the file needs to go next.
Common use cases
People convert AVI to MKV for jobs such as high-quality film archives and multi-language and multi-subtitle collections. It is especially common when a AVI file arrives from one system but needs to work in another that standardises on MKV.
When to convert AVI to MKV
Reach for AVI to MKV when your destination expects MKV — for example high-quality film archives and multi-language and multi-subtitle collections. It is the right move when you receive a AVI file but the app, website, or person you are working with cannot use it. Bear in mind that limited native support on mobile and browsers, so keep your original AVI if you might need it again.
How to convert AVI to MKV
- Upload your AVI file to the converter at the top of this page - MKV is already selected as the output.
- Check the size limit shown on this page, then drag and drop or browse for your file.
- Confirm MKV is still the target format, or pick a different one from the grid.
- Start the conversion and download your MKV file the moment it is ready.
Quality tips
Keep one master AVI archived and convert copies. If the MKV file is for web playback, test it in the target browser or player; if you only need the sound, use our Extract Audio tool instead of a full video conversion.
Platform compatibility
The AVI to MKV converter runs on Windows, macOS, Linux, Android, and iOS - anywhere with a modern browser, with no plugins or permissions required. Once exported, MKV opens in VLC and most desktop media players.
File size limits
Video/audio up to 2GB
Troubleshooting
- If the file exceeds the limit shown below, compress images, trim video, or split archives before retrying.
- If conversion fails, confirm the extension matches the real format — renaming a file alone does not change its contents.
- Very large videos process faster if you trim them first with our Video Trim tool.
- If quality looks soft, try a less aggressive setting when the converter offers options.
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