Will I lose quality converting AVI to MKV?

No. This is a container remux, not a re-encode. The H.264, MPEG-4, or DivX/Xvid video stream and whatever audio codec is already inside your AVI file is copied byte-for-byte into the new MKV wrapper. There is no generation loss, no re-compression artifacts, and no change to resolution, bitrate, or frame rate.

Why is my AVI file exactly 2 GB or oddly split into multiple parts?

That is the classic OpenDML/AVI1 size limitation. Older camcorders, capture cards, and encoding software wrote AVI files with a 32-bit size field that overflows around 2 GB, so long recordings get split into 2GB.AVI, 2GB(2).AVI and so on. MKV has no such limit — converting each part and later using a video merge tool lets you produce one continuous file.

What is MKV and why do Plex and Jellyfin prefer it?

MKV (Matroska) is an open-source, patent-free container that supports essentially any codec plus multiple audio tracks, multiple subtitle tracks, and chapter markers in one file. Home media servers like Plex and Jellyfin favor it because a single MKV file can carry a movie's video, several audio languages, and several subtitle languages, letting the app switch between them without needing separate files.

Can I add subtitles to the MKV after converting?

Yes. Once your AVI is repackaged as MKV, you can use a subtitle-muxing tool or media player like MKVToolNix to attach an external .srt or .ass subtitle file as a separate track without touching the video or audio streams again.

Does the conversion work if my AVI uses an old codec like DivX, Xvid, or Cinepak?

Yes, as long as your media player or server has a decoder for that codec installed. The remux does not change the codec — it only changes the container — so if DivX video played in your AVI file before, it will still need a DivX-capable decoder to play after conversion to MKV.

Why would I keep AVI instead of switching everything to MKV?

AVI still has near-universal support in very old software and some embedded devices (certain digital signage players, legacy industrial systems, and pre-2010 DVD authoring tools) that were never updated to read Matroska. If your only playback target is one of those, staying in AVI may be simpler.

Will the audio and video stay in sync after conversion?

Yes. Because the tool performs a direct stream copy rather than re-encoding, the original timestamps are preserved from the source AVI, so any sync that existed before conversion carries over unchanged.

Is there a limit to how many AVI files I can convert?

No daily limit on the number of conversions. File size is capped by your plan — 40 MB without an account, 80 MB after a free sign-up, and 250 MB on Pro — because everything processes inside your browser's available memory rather than on a server.

Can I convert an AVI with no audio track?

Yes. If your AVI is video-only (common for screen recordings or silent camera footage), the remux simply carries over the video stream and produces a valid MKV with no audio track.

Do I need to install FFmpeg or any software?

No. FFmpeg runs as WebAssembly directly inside your browser tab. There is nothing to install, and the ~30 MB FFmpeg engine only needs to download once per browser session.

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What is AVI to MKV?

AVI (Audio Video Interleave) is a container format Microsoft introduced in 1992 as part of Video for Windows. It was built for a world of CD-ROMs and low-resolution codecs, and that origin still shows: the original AVI spec has a 32-bit size field that causes corruption or forced splitting past roughly 2 GB unless the OpenDML extension is used, it has no native concept of chapters or multiple subtitle tracks, and variable frame rate video — extremely common in modern phone and screen recordings — is stored awkwardly because AVI expects a fixed frame interval. None of that is a problem with the codec inside the file; it is a limitation of the wrapper around it.

MKV (Matroska) was designed from scratch in the mid-2000s to fix exactly these gaps. It can hold any video or audio codec, any number of subtitle tracks in any format (including styled ASS/SSA subtitles), chapter markers, attached fonts, and cover art, all indexed in a way that survives file corruption far better than AVI's linear index. This tool converts your AVI file to MKV using a direct stream copy — the video and audio data is not re-encoded, decoded, or recompressed, it is simply repackaged into the Matroska container structure. That means the conversion is nearly instant regardless of file length, and the output is bit-for-bit identical in picture and sound quality to your original AVI.

How It Works

FFmpeg WebAssembly loads your AVI file into browser memory and reads its stream headers to identify the video and audio codecs already inside it. Because MKV can wrap almost any codec without conversion, the tool runs a stream copy (-c copy) that lifts the existing compressed video and audio data out of the AVI container and writes it directly into a new Matroska container, rebuilding the index and timestamp tables along the way. No pixels are decoded and no audio samples are re-encoded, which is why even a two-hour AVI file typically finishes in a few seconds rather than the minutes a full re-encode would take.

How to Use

Upload your AVI file

Drag your .avi file onto the upload zone or click to browse. The file loads directly into your browser's memory — nothing is sent anywhere yet.

Wait for the FFmpeg engine to load

On your first conversion, the browser downloads the ~30 MB FFmpeg WebAssembly engine. This is cached afterward so future conversions on this site start instantly.

Click Convert to MKV

FFmpeg reads the AVI's existing video and audio streams and remuxes them directly into a new Matroska container — no re-encoding, no quality loss.

Watch the progress bar

Because this is a stream copy rather than a re-encode, most AVI files finish in seconds even if they are several gigabytes in size.

Download your MKV file

Click the download button to save the finished .mkv file to your device. Your original AVI file is untouched and still available.

Play or import it

Open the MKV in VLC, Kodi, Plex, or Jellyfin, or add it to your home media library. If needed, use MKVToolNix afterward to attach subtitle tracks.

Who Uses This Tool

🎞️

Digitized Home Video Libraries

Old camcorder or capture-card footage stored as AVI often gets split into 2 GB chunks. Converting to MKV removes that ceiling so a full recording can live in one file.

🗂️

Adding External Subtitles

AVI has no reliable way to hold multiple subtitle tracks. Repackage as MKV first, then mux in .srt or .ass subtitle files without re-encoding the video.

💾

Home Media Server Migration

Plex and Jellyfin index and scrub MKV more reliably than AVI, and can carry multi-language audio in one file — convert an older AVI library for a smoother server experience.

📺

HTPC and Kodi Setups

Home theater PC builds running Kodi rely on chapter markers and rich metadata that AVI cannot store natively but MKV supports out of the box.

🗄️

Long-Term Archival

MKV is an open, royalty-free specification maintained independently of any single company, making it a safer long-term archival choice than a proprietary or aging format.

✂️

Restoring Split Recordings

If a long AVI recording was auto-split by your capture software at the 2 GB boundary, converting each part to MKV and then merging them produces one seamless file.

Why Choose This Tool

Lossless Stream Copy, Not a Re-encode

AVI content is remuxed into MKV by copying the existing compressed streams directly — zero quality loss and conversion speed that depends on file size, not video length.

Removes the 2 GB AVI Ceiling

Once your footage lives in Matroska, there is no legacy 32-bit size restriction to worry about, so long recordings no longer need to be split into parts.

100% Browser-Based Processing

FFmpeg WebAssembly does the remuxing locally on your device — your AVI file is never uploaded to a server, which matters for personal or sensitive footage.

Room for Multiple Tracks Later

MKV output can hold multiple audio tracks, subtitle streams, and chapter metadata, so you can extend the file later without another format change.

No Server-Side Upload Caps

Because everything happens in your browser's memory, there is no arbitrary server timeout or upload cap tied to your internet connection speed.

Free to Start — Sign Up for More

Use free with no account for files up to 40 MB. Sign up free to raise your limit to 80 MB, or upgrade to Pro for 250 MB per file.

Key Benefits

Lossless remux — video and audio are copied, not re-encoded

Handles files with no practical size ceiling since MKV removes the 2 GB AVI limit

Browser-based — the AVI file never leaves your device

Output plays natively in Plex, Jellyfin, VLC, and Kodi

Supports adding external subtitle tracks after conversion

Rebuilds a clean, seek-friendly index for scrubbing playback

No account needed for files up to 40 MB

100% free with no watermark on the output file

Frequently Asked Questions

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AVI to MKV

What is AVI to MKV?

How It Works

How to Use

Who Uses This Tool

Why Choose This Tool

Key Benefits

Frequently Asked Questions

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