Add your MKV file
Drop one or more .mkv files onto the converter above, or browse for them. They load into browser memory only — nothing is uploaded, so there is no size-based pricing and no server queue.
MKV to 3GP
Pulling the soundtrack out of a .mkv video into .3gp audio keeps what you can hear and drops the picture entirely. Free, private, and validated — the file never leaves your browser.
Private for supported formats — processed in your browser
Runs on your deviceConvert supported files
Drop MKV files here
Batch files can each use a different output. Nothing uploads for local conversions.
Working inputs include camera RAW, browser-local audio/video, PDF, CBZ/CBR comics, office documents, ebooks, markup, 3D models, structured text, images, and archives.About converting Matroska video to 3GPP video
Pulling the soundtrack out of a .mkv video into .3gp audio keeps what you can hear and drops the picture entirely. An .mkv file uses the Matroska container, an open format designed to hold an unlimited number of video, audio, and subtitle tracks in one file. Collectors of high-quality rips and archival copies favor .mkv because it keeps every language track, chapter marker, and font attachment together.
A .3gp file is a lightweight container defined by the 3GPP standards body for video recorded and shared on mobile phones. It packs low-bitrate video and compressed speech with minimal overhead, which made .3gp the format of MMS messages and early camera phones. For this route the practical draw is extremely small files by design and structural kinship with MP4 makes conversion quick — balanced against picture quality is poor by any modern standard, which is worth knowing before you commit a large batch.
Why convert MKV to 3GP?
The usual reason to take .3gp audio out of a .mkv file is that only the sound matters — a talk, interview, song, or podcast segment. Keeping the video stream would waste storage, and a dedicated audio file is easier to trim, tag, and play. On the source side, safari and iOS refuse the container outright; on the target side, the payoff is extremely small files by design, which is exactly what you want for recovering videos from old feature phones and their memory cards.
MKV vs 3GP at a glance
| Aspect | Matroska video (.mkv) | 3GPP video (.3gp) |
|---|---|---|
| Format type | Container — quality depends on the codecs and settings inside | Container — quality depends on the codecs and settings inside |
| How it stores data | built on EBML, a binary XML-like structure that lets the container gain features without breaking older parsers | iSO base media structure like MP4, but with a deliberately restricted codec list |
| Strongest at | archiving discs while preserving every audio track and subtitle stream | recovering videos from old feature phones and their memory cards |
| Weak spot | safari and iOS refuse the container outright | picture quality is poor by any modern standard |
| Metadata | matroska tags cover title, cast, and arbitrary key-value pairs, and the container can embed cover art and other files as attachments | a small set of 3GPP-defined asset atoms for title, author, and location exists, though most recording phones never wrote them |
Pick 3GP as the output
Select .3gp in the output menu next to each file. The menu only offers targets this engine can genuinely produce, so if 3GP is selectable, the route is real and validated.
Convert on your device
Press Convert. A WebAssembly FFmpeg build demuxes the audio track and re-encodes it locally; the video stream is simply discarded.
Verify and download
Each result is signature-checked before the download unlocks, so a failed encode can never masquerade as a valid 3GP file. Outputs keep the original filename with the .3gp extension.
MKV to 3GP questions, answered
Will converting MKV to 3GP lose quality?
Since mkv is container-oriented and 3gp is container-oriented, the conversion preserves the source content exactly as stored; no additional compression pass is applied beyond what .3gp itself requires.
Is it private to convert MKV files here?
Yes — the .mkv file is processed inside your browser tab and never uploaded. A WebAssembly FFmpeg build demuxes the audio track and re-encodes it locally; the video stream is simply discarded. Close the tab and the file is gone from memory.
Where will the 3GP file work?
Android still opens most .3gp files, and desktop players such as VLC handle them, but iOS and web browsers generally do not. Because the codecs inside are dated, converting to MP4 with AAC audio is the standard path to modern playback.
Will the 3GP file be bigger or smaller than my MKV?
Much smaller — the video stream is usually 80–95% of a .mkv file's weight, and it is discarded entirely. The remaining audio is re-encoded at the bitrate implied by your quality setting.
What happens to the metadata in my MKV file?
This converter strips container metadata deliberately (the FFmpeg command runs with metadata mapping disabled) so exported files do not leak recording details. In the source, matroska tags cover title, cast, and arbitrary key-value pairs, and the container can embed cover art and other files as attachments; none of it is transmitted anywhere because the file never leaves your browser.
Can I convert 3GP back to MKV?
Yes — the reverse route exists as a separate tool. Bear in mind that round-tripping .mkv → .3gp → .mkv is not a perfect undo when any lossy step is involved; keep your original if fidelity matters.