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3GP to MKV

3GP to MKV Converter

Drop a 3GP file into the converter below and download a MKV seconds later. No account, no watermark, no file size limit. MKV is an open container that can hold multiple audio tracks and subtitles — preferred for archival and media servers.

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Convert 3GP → MKV directly in Claude Code, Cursor, or Claude Desktop
One-line MCP install. Runs native ffmpeg locally — ~5–10× faster than the browser version.
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How to convert 3GP to MKV
  1. 1
    Drop your file
    Drag & drop a .3gp file into the zone below, or click to browse. Multiple files work too.
  2. 2
    Convert in browser
    Hit Convert — FFmpeg-WebAssembly transcodes your 3GP into MKV locally. Nothing is uploaded.
  3. 3
    Download result
    Save the converted .mkv file to your device. Repeat with more files or pick a different target format.
Why this converter
Free forever
No paywalls, no sign-up.
No watermarks
Your output is clean — no logos, no overlays.
100% private
Files are converted on your device, never uploaded.
Works offline
After first load, conversion works without internet.
Batch & multi-file
Drop a whole folder — we'll ZIP the output.
Open source
Review, fork, or host the code yourself.
FAQ

A .mkv file is a Matroska video container — open format, holds multiple tracks and subtitles. It's a container that holds compressed video and audio streams.

MKV is an open container that can hold multiple audio tracks and subtitles — preferred for archival and media servers.

Yes — conversion runs entirely inside your browser using WebAssembly. Your files never leave your device, never touch our servers, and we have no way to see or store them. Open DevTools → Network tab while converting; you'll see zero upload traffic.

Video and audio conversion works on iOS 16.4 and later (requires SharedArrayBuffer support). Older iPhones can still convert images without issues.

There's no hard limit we enforce, but the converter is bounded by your device's RAM. Phones typically handle files up to ~500MB comfortably; laptops can push into multi-GB territory. If your file is very large, try splitting it first.

Most online converters upload your file to their servers, process it there, and let you download the result. That means trusting them with potentially sensitive media. This tool skips the server entirely — the same FFmpeg code runs in your browser via WebAssembly, so nothing is uploaded, nothing is stored, and it's free forever.

Related converters
MKV→3GP›3GP→GIF›3GP→MP4›3GP→WebM›GIF→MKV›MP4→MKV›