Convert any audio file to MKV format online for free. Fast, secure, and easy-to-use audio to MKV converter with no software installation required.
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Max file size: 50 MBMax duration: 30 min
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Drag and drop your 3GP file, or click to browse for it.
Choose MKV as the output and click Convert. The conversion runs on our servers, so your device does none of the work.
Download your converted file instantly. The download link expires in 1 hour for security.
Our powerful servers process your files quickly, delivering converted files in seconds.
Convert your files completely free with no hidden costs or subscription fees.
Your file is used only to make your conversion. It is never published or shared, and the download link expires after one hour.
Works directly in your web browser. No software download or installation required.
How the two formats differ on the things that change your result.
| Specification | 3GP (source) | MKV (result) |
|---|---|---|
| Container | 3GPP | Matroska |
| Developed by | 3GPP | Matroska.org |
| Introduced | 2001 | 2002 |
| Video codecs | H.263, MPEG-4 Part 2, H.264 | H.264, H.265, VP9, AV1 |
| Audio codecs | AMR-NB, AMR-WB, AAC-LC | AAC, FLAC, Opus, AC-3, DTS |
| Max resolution | Standard definition | 8K UHD |
| Typical bitrate (1080p) | 0.2–2 Mbps | 8–40 Mbps |
| Multiple audio tracks | No | Yes |
| Subtitle tracks | Limited support | Embedded (soft) subtitles |
| Chapter markers | No | Yes |
| Streaming optimized | Yes | No |
| Licensing | Patent-licensed | Royalty-free |
| Plays natively on | Native: Android · Needs a player: Windows, macOS, iOS | Native: Windows · Needs a player: macOS, iOS, Android, Smart TVs |
| Best for | phone recordings, low-bandwidth delivery, older phones | media archives, multi-language releases, home theatre |
Because MKV supports H.264 just like 3GP does, the video stream can be carried across without a quality-costing re-encode.
At 1080p, 3GP typically runs around 1.1 Mbps while MKV sits near 24 Mbps, which is the main driver of the size difference you will see.
This is an older container, introduced in 2002, and browsers will not play it directly. It is best suited to archival or a dedicated player.
This page converts 3GP video, stored in the 3GPP container since 2001, into MKV, which uses Matroska and dates from 2002. The codecs each container accepts decide whether the picture has to be re-encoded.
3GP comes from 3GPP and dates to 2001. It usually holds H.263, MPEG-4 Part 2, or H.264 video with AMR-NB, AMR-WB, or AAC-LC sound, and those streams set the ceiling for anything converted out of it.
MKV comes from Matroska.org and dates to 2002. It holds H.264, H.265, VP9, or AV1 video alongside AAC, FLAC, Opus, AC-3, or DTS audio, and without installing anything it plays on Windows.
After converting your file, you can use Scriptivox transcription services to convert your audio to text. Perfect for meetings, interviews, podcasts, and more.
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