Convert 3GPP2 Multimedia (.3g2) to Matroska Video (.mkv) online for free. Fast, secure video conversion with no watermarks or registration.
Upload your .3g2 file by dragging it into the upload area or clicking to browse.
Choose your output settings. The default settings work great for most files.
Click Convert and download your .mkv file when it's ready.
MKV (Matroska Video) is the Swiss Army knife of video containers — it supports virtually every video and audio codec ever created, multiple subtitle tracks, chapter markers, and rich metadata. Converting 3G2 to MKV transforms old CDMA phone recordings from the cramped 3GPP2 container into Matroska's flexible and future-proof structure. MKV is the format of choice for media archivists, Kodi/Plex users, and anyone who values container-level flexibility.
While MKV may seem like overkill for tiny phone recordings, the container's ability to carry arbitrary metadata, support any codec without re-encoding, and maintain perfect stream fidelity makes it an excellent archival target. You can remux the original 3G2 streams into MKV without any re-encoding, preserving every bit of the original recording.
MKV's primary advantage is universal codec support without the container-level restrictions found in MP4 or AVI. If you want to preserve the original H.263 or MPEG-4 Part 2 video and AMR audio from your 3G2 files exactly as recorded — without any re-encoding — MKV can hold these streams directly. This is a true archival remux with zero quality change.
Additionally, MKV integrates seamlessly with media server software like Plex, Jellyfin, and Kodi. If you are building a media library that includes old phone recordings alongside movies and TV shows, MKV provides a consistent container format. MKV also supports attaching files (like photos or documents) to the video, which can be useful for contextual archival — embedding the source phone's photo or the original 3G2 file as an attachment.
For remuxing (preserving original codecs), FFmpeg copies the H.263 or MPEG-4 Part 2 video and AMR or AAC audio streams directly into the Matroska container using '-c copy'. This is virtually instantaneous and lossless. For transcoding to modern codecs, FFmpeg can re-encode to H.264/H.265 video with AAC/Opus audio inside MKV. The mkvmerge tool from MKVToolNix can also be used for advanced MKV operations like adding chapters, subtitles, and file attachments.
When remuxing (stream copy), quality is identical to the source — every frame and sample is preserved bit-for-bit. When transcoding to H.264, quality depends on the target bitrate but can match or slightly exceed the original at equivalent file sizes due to H.264's superior compression efficiency. MKV as a container adds no quality overhead in either mode.
| Device | 3G2 | MKV |
|---|---|---|
| Windows PC | Partial | Partial |
| macOS | Partial | Partial |
| iPhone/iPad | Partial | Partial |
| Android | Native | Partial |
| Linux | Partial | Partial |
| Web Browser | No |
Resolution: 1920x1080
Bitrate: 8-12 Mbps
H.264 recommended for fast processing
Resolution: 1080x1080
Bitrate: 3.5 Mbps
Square or 9:16 for Reels
Resolution: 1080x1920
Bitrate: 4 Mbps
9:16 vertical, under 60s ideal
Resolution: 1280x720
Bitrate: 5 Mbps
Under 140s, 512MB max
Resolution: 960x540
Bitrate: 2 Mbps
16MB limit for standard, 64MB for document
Resolution: 1280x720
Bitrate: 4 Mbps
Converting 3G2 to MKV provides maximum flexibility for archival and media server integration. The remux option preserves original quality instantly, while transcoding to modern codecs offers better compression and wider player support.
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Mọi trình duyệt, mọi thiết bị
| Tính năng | 3G2 | MKV |
|---|---|---|
| Tên đầy đủ | 3GPP2 Multimedia | Matroska Video |
| Phần mở rộng | .3g2 | .mkv |
| Phù hợp nhất cho | Mobile optimized | Multiple audio tracks |