AVI to MKV Converter
Move old AVI videos into the flexible MKV container for media libraries and archiving — free, no signup, no watermark.
up to 50 files at once
auto-delete in 24h · no signup · no watermark
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How to convert AVI to MKV online
- Click "Browse Files" or drag your AVI file into the converter above (up to 200 MB free, 500 MB with an account).
- The target format is preset to MKV — adjust quality options in the picker if you need to.
- Hit "Convert". Your file uploads over an encrypted connection and converts automatically in the cloud — nothing to install.
- Click the green "Download" button to save your MKV file. The original is deleted immediately and the result auto-deletes after 24 hours.
That is the entire flow — no email address, no software install, no watermark on the output. The page you are reading handles AVI to MKV from start to finish.
What's the difference between AVI and MKV?
AVI (Audio Video Interleave) and MKV (Matroska Video) solve different problems: AVI is a media container format built for legacy video files, old camera footage, while MKV is a media container format whose strength is movie archives, multi-audio/subtitle videos. In practice you will meet AVI when dealing with legacy video files, old camera footage, and reach for MKV when you need movie archives, multi-audio/subtitle videos — the table below compares them point by point.
| AVI | MKV | |
|---|---|---|
| Full name | Audio Video Interleave | Matroska Video |
| Developed by | Microsoft | Matroska.org (open source) |
| Released | 1992 | 2002 |
| Compression | Media container | Media container |
| Typical use | legacy video files, old camera footage | movie archives, multi-audio/subtitle videos |
| File extension | .avi | .mkv |
| MIME type | video/x-msvideo | video/x-matroska |
Why convert AVI to MKV?
AVI (Audio Video Interleave) is a video container Microsoft introduced in 1992. One of the oldest video formats still in circulation, it lacks modern features like streaming support and efficient codecs, so old AVI files are usually converted to MP4 for use on today's devices. Here is when MKV is the better choice:
- →MKV holds unlimited audio and subtitle tracks — ideal for movie libraries.
- →It runs in the cloud — 10 free conversions a day with files up to 200 MB (20/day and 500 MB with a free account) — so even a phone or an old laptop converts at full speed.
Before you convert: three quick tips
- ●Video conversion time scales with length — for long footage, trimming to the segment you need before converting saves both time and quota.
- ●Posting to social platforms? MP4 is the universally accepted choice. Short looping clips? GIF. Embedding on a web page you control? WebM is worth considering.
- ●Keep your original AVI — conversion never modifies it, and if you later need a different target format, starting from the original always gives the best quality.
MKV conversion settings explained
Filevo encodes video with H.264 at CRF 23 using the veryfast preset, with faststart enabled — the engineering balance of compatibility, quality, and speed: the output plays on any device and starts instantly when streamed.
The audio track is encoded as AAC at 128 kbps (higher available in options). Resolution matches the source, auto-adjusted to even dimensions as the encoder requires.
How the conversion works
Filevo's AVI to MKV conversion is powered by FFmpeg, the open-source media framework behind much of the world's video infrastructure. We run it with compatibility-first settings tuned for everyday playback, and stream progress back to your browser in real time. Because everything runs in the cloud, your device's CPU stays idle — the browser only uploads and downloads.
Why convert AVI to MKV?
MKV (Matroska) is the preferred container for media libraries, archiving and high-quality distribution. It can hold virtually unlimited video, audio and subtitle tracks, plus chapters, attachments and tags — all in one self-contained file. Converting AVI to MKV brings an old video out of a rigid, dated container into a modern, future-proof one, ideal for organizing a collection in Plex or Jellyfin or keeping a tidy long-term archive.
Built for media libraries
Where AVI carries just one video and one audio track, MKV is built to grow: you can later add multiple audio languages, subtitle tracks (from simple SRT to styled ASS and Blu-ray PGS), chapters and metadata, and it supports modern codecs from H.264 and HEVC to VP9 and AV1. Moving your AVI into MKV gives it a home that media servers index cleanly and that won’t hold your collection back as it grows.
An honest note on what carries over
To be clear: an AVI only has one video and one audio track to begin with, so converting to MKV doesn’t magically add languages or subtitles — those would be things you add later. What the MKV container gives you now is room to grow and a modern, archive-grade home for the video, plus cleaner handling in media-server software. The picture and sound from the AVI carry over as-is into the more capable container.
Convert AVI to MKV on any device
On Windows or Mac, where most AVI files live: drag the AVI straight from Explorer or Finder into the converter above. On iPhone or Android: open this page in your browser, tap Browse Files and pick the AVI — no app required. Everything runs in the cloud, and the MKV downloads ready for your media library or archive.
What is AVI?
AVI (Audio Video Interleave) is a video container Microsoft introduced in 1992. One of the oldest video formats still in circulation, it lacks modern features like streaming support and efficient codecs, so old AVI files are usually converted to MP4 for use on today's devices.
| Full name | Audio Video Interleave |
| Developer | Microsoft |
| Released | 1992 |
| MIME | video/x-msvideo |
What is MKV?
MKV (Matroska Video) is an open-source container format released in 2002 that can hold unlimited video, audio, and subtitle tracks in one file. Loved for movie archiving and high-quality rips, it is not supported by iPhones, many TVs, and most editing apps — hence the constant MKV-to-MP4 conversions.
| Full name | Matroska Video |
| Developer | Matroska.org (open source) |
| Released | 2002 |
| MIME | video/x-matroska |
Filevo vs other AVI to MKV converters
An honest comparison — CloudConvert and Convertio are capable tools; here is where Filevo differs:
| Filevo | CloudConvert | Convertio | |
|---|---|---|---|
| Free tier | 10/day | 10/day | 10 credits/day |
| No signup needed | Yes | Yes | Yes |
| Watermarks | None | None | None |
| Ads on free tier | No | No | Yes |
| Pricing model | 1 file = 1 credit, shown upfront | Per conversion minute | Credit packs |
Privacy & file security
Filevo deletes your uploaded AVI file immediately after conversion and removes the converted MKV within 24 hours. Everything travels over TLS encryption, processing is fully automated with zero human access, and your files are never used for AI training. See our Privacy Policy for details. Privacy Policy →
AVI to MKV converter FAQ
How do I convert AVI to MKV for free?
Drop your AVI file into the converter at the top of this page, confirm MKV as the target, click Convert, and download the result. It is genuinely free: 10 free conversions a day with files up to 200 MB (20/day and 500 MB with a free account), no watermarks, no software to install, no account required.
Is it safe to convert AVI files online?
Yes. Transfers are TLS-encrypted end to end, and conversion is fully automated — no human ever sees your files. Your uploaded AVI is deleted the moment conversion finishes, and the converted MKV auto-deletes after 24 hours (you can delete it sooner). We never use your files for AI training or share them with anyone.
Will I lose quality converting AVI to MKV?
Video is re-encoded with H.264 at CRF 23 (veryfast preset) — a quality level that is visually indistinguishable from the source for normal viewing. Keep your original file if you need a frame-perfect master.
How long does AVI to MKV conversion take?
It depends on length and resolution: short clips typically finish in well under a minute, while longer videos process at roughly real-time speed or faster. Upload time depends on your connection — for large files, uploading is usually the longest step.
Can I convert AVI to MKV on iPhone or Android?
Yes. Filevo runs entirely in the browser, so it works the same on iPhone, Android, tablets, and computers — no app to install. On mobile, tap Browse Files to pick from your photos or files.
What's the maximum file size?
Anonymous conversions accept files up to 200 MB; a free account raises that to 500 MB. Paid plans go from 1 GB up to 10 GB per file, with higher daily limits and priority queues.
Can I convert multiple files at once?
Yes. Drop up to 50 files at once — they roll through the queue automatically. Pick a target format per file or set one per category, then download results individually or grab everything as a single ZIP.
What will the converted file be named?
Your original name is kept and only the extension changes — holiday.avi becomes holiday.mkv, so files stay easy to find.
Why use MKV for archiving old AVI videos?
MKV is the standard container for media libraries and archives — it’s flexible, future-proof, supports modern codecs and unlimited tracks, and is indexed cleanly by servers like Plex and Jellyfin. Moving AVI into MKV gives your old videos a modern, organized home.
Does converting AVI to MKV add subtitles or extra tracks?
No — an AVI only has one video and one audio track, so there’s nothing extra to carry over. What MKV adds is the capability: you can later add subtitle and audio tracks, chapters and metadata to the MKV. The conversion itself moves the existing picture and sound into the more capable container.
Will my MKV play everywhere the AVI did?
Not quite — MKV isn’t supported by some old devices, iPhones or certain TVs that may still read AVI. MKV is ideal for media servers and archiving rather than legacy hardware. If you need to play on old gear, AVI or MP4 is the safer target; for a modern library, MKV wins.
Whether you need movie archives, multi-audio/subtitle videos or simply a file that works where AVI will not open, the converter above turns AVI into MKV in seconds — free, private, and with nothing to install. Bookmark this page for the next time a AVI file refuses to cooperate.
Last updated: 2026-07-27