Theora to MP4 (H.265) - Online Video Converter
Convert Theora to MP4 (H.265) online. Private, client-side - no uploadrequired. Batch conversion, quality presets, codec control.
About Theora to MP4 (H.265)
Convert Theora to MP4 (H.265). Theora is Xiph's open video codec paired with Vorbis audio. MP4 (H.265) stores HEVC video, cutting bitrate roughly in half versus H.264. HEVC decoding needs newer hardware and encodes more slowly..
Why convert Theora to MP4 (H.265)?
- Smaller files with MP4 (H.265) lossy compression.
- Keep animation and transparency where supported.
- Private, no upload - runs in your browser.
Theora vs MP4 (H.265)
| Animation | Yes | Yes |
|---|---|---|
| Transparency | No | No |
| Compression | lossy | lossy |
| Typical use | Theora is Xiph's open video codec paired with Vorbis audio. | MP4 (H.265) stores HEVC video, cutting bitrate roughly in half versus H.264. |
When not to convert Theora to MP4 (H.265)
- Skip MP4 (H.265) 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 MP4 (H.265) 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. HEVC decoding needs newer hardware and encodes more slowly. Encode MP4 (H.265) (H.265 / 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.