Theora to MKV - Online Video Converter
Convert Theora to MKV online. Private, client-side - no uploadrequired. Batch conversion, quality presets, codec control.
About Theora to MKV
Convert Theora to MKV. Theora is Xiph's open video codec paired with Vorbis audio. MKV is an open container holding multiple video, audio, and subtitle tracks. Only the selected tracks carry over, so pick audio and subtitles first..
Why convert Theora to MKV?
- Smaller files with MKV lossy compression.
- Keep animation and transparency where supported.
- Private, no upload - runs in your browser.
Theora vs MKV
| Animation | Yes | Yes |
|---|---|---|
| Transparency | No | Yes |
| Compression | lossy | lossy |
| Typical use | Theora is Xiph's open video codec paired with Vorbis audio. | MKV is an open container holding multiple video, audio, and subtitle tracks. |
When not to convert Theora to MKV
- Skip MKV for archival masters: lossy compression discards detail, so keep the Theora original.
- Keep a master copy: repeated exports stack small losses, so archive Theora before batch MKV shares.
Limits
Starting point: Theora - Theora is Xiph's open video codec paired with Vorbis audio. Ogg multiplexing quirks can offset sync; verify after conversion. Only the selected tracks carry over, so pick audio and subtitles first. Encode MKV (H.264 / AAC) from Theora at a bitrate near the source, and confirm the audio track before converting.
How conversion works
Conversion runs entirely in your browser with FFmpeg WASM. Files never leave your device.