AVI to MKV Converter

Convert AVI to MKV online for free. AVI to MKV in seconds — no software install, no watermark, secure and fast.

Drag & drop your AVI file here, or

How to convert AVI to MKV in 3 steps

  1. 1

    Upload your AVI file

    Drag and drop or select the AVI file you want to convert.

  2. 2

    Choose MKV as output

    The output format is pre-selected for you — just confirm and start the conversion.

  3. 3

    Download your file

    Once processing finishes, download your converted MKV file instantly.

Benefits of converting AVI to MKV

Get support for multiple audio/subtitle tracks and near-lossless quality

Switching from AVI to MKV means your file now offers support for multiple audio/subtitle tracks and near-lossless quality, ideal for archiving.

Wider compatibility

AVI is great for simple, but not every app or device handles it well. Converting to MKV sidesteps that, so the file opens wherever you need it to.

No quality compromise

ConvertFastHub runs FFmpeg at production settings, preserving as much of the original AVI fidelity as the MKV format allows.

Keep your original too

Converting doesn't touch your source file — you get a brand-new MKV file back and can keep both versions.

Frequently asked questions

How do I convert AVI to MKV online?
Upload your AVI file above, select MKV as the output format, and click Convert. ConvertFastHub processes the file in the cloud and gives you a download link — no software installation required.
Is it free to convert AVI to MKV?
Yes. Free accounts get 10 conversions every 24 hours with files up to 50MB. For unlimited conversions, larger files up to 1.5GB, and priority processing, upgrade to ConvertFastHub Pro.
What's the advantage of MKV over AVI?
MKV offers support for multiple audio/subtitle tracks and near-lossless quality, ideal for archiving. Meanwhile, AVI is known for simple, widely-supported legacy playback on older hardware — the right choice depends on where you plan to use the file.
Will converting AVI to MKV reduce quality?
ConvertFastHub uses production-grade engines (FFmpeg, LibreOffice, ImageMagick) configured for maximum fidelity. Some format conversions are inherently lossy by design; where possible, we preserve the original quality.
Is my file safe when I convert it?
Files are uploaded over an encrypted connection directly to storage, processed in an isolated sandboxed worker, and permanently deleted within 24 hours.