3GP to MKV Converter
Convert 3GP to MKV free — no upload, no signup
To convert 3GP to MKV, drop your 3GP video into the box below and click Convert. Fylo converts with ffmpeg running inside your browser, so nothing is uploaded and there's no signup or watermark. Repackage 3GP into MKV with no re-encoding.
Drop videos here
or tap to browse · paste with Ctrl+V · add many at once
Your files never leave your device
If the video already uses codecs that fit the new format, Fylo repackages it instantly with no quality loss.
Advanced
How to convert 3GP to MKV
Add your 3GP videos
Drag and drop 3GP files into the box or tap to choose them. The converter engine (about 31 MB) downloads once, the first time you convert.
Choose quality (optional)
Balanced quality suits most videos. If the codecs already fit MKV, Fylo repackages the file instead of re-encoding it, with no quality loss.
Convert and download
Click Convert, then download each MKV file or all of them as one ZIP.
Why convert 3GP to MKV?
Archiving old phone videos in MKV keeps them playable in VLC, Plex and Kodi.
What happens when you convert 3GP to MKV?
The streams are copied into Matroska; nothing is re-encoded.
How does Fylo convert 3GP to MKV?
Fylo reads the 3GP with ffmpeg compiled to WebAssembly and writes a straight copy of every stream — Matroska accepts any codec, so nothing is re-encoded. Every conversion to MKV is a lossless repackage, so it finishes in seconds even for large files. Only the first video and audio track are kept, and the original resolution is preserved unless you pick 1080p, 720p or 480p under Advanced.
What's the difference between 3GP and MKV?
3GP was defined by the 3rd Generation Partnership Project for 3G mobile phones and MMS messaging. It's based on the same ISO media structure as MP4 but restricted to phone-friendly codecs such as H.263 or H.264 Baseline video and AMR or AAC audio.
MKV is the Matroska container, an open standard first released in 2002. It can hold virtually any video, audio or subtitle codec, and any number of tracks — so one file can carry several languages, director's commentary and subtitles. WebM is a restricted subset of Matroska.
Learn more: 3GP format guide · MKV format guide
| Property | 3GP | MKV |
|---|---|---|
| Developed by | 3rd Generation Partnership Project (3GPP) | Matroska project (open standard) |
| Introduced | 2002 | 2002 |
| Typical video codecs | H.263, H.264 (Baseline) | Any: H.264, HEVC, VP9, AV1… |
| Typical audio codecs | AMR, AAC | Any: AAC, Opus, FLAC, DTS, AC-3… |
| Plays in web browsers | Partly | Partly (Chrome/Edge for some codecs) |
| Compatibility | Old feature phones, most media players | VLC, Plex, Kodi, most smart TVs; not iPhone or many editors |
| Best for | Very small videos for old phones and MMS | Movies with multiple audio and subtitle tracks |
Frequently asked questions
Is it lossless?
Yes.
Will all players handle AMR audio?
Most desktop players do; convert to MP4 for phones.
Is my 3GP file uploaded to a server?
No. Fylo runs ffmpeg, the same engine used by professional video tools, compiled to WebAssembly inside your browser. Your 3GP file is read directly from your device and never sent anywhere.
Related tools
Updated