MKV to WEBM Converter

Kept

• Matroska files with H.264, H.265 and other codecs are read, including Blu-ray and anime rips
• VP9 video with Opus audio, the open format that browsers and web players use
• The original resolution and frame rate are kept
• A phone video recorded sideways or upside down is turned the right way up

Good to know

• Extra audio tracks and subtitles are not carried over.
• Audio with more than two channels (5.1 surround) is mixed down to stereo.
• The encoder runs in its fastest mode to finish in time, so the file is somewhat larger than a slow VP9 encode would give.
• Older TVs, some iPhones with old iOS and many video editors cannot open WebM. Choose MP4 for those.
• The video is re-encoded, which is slightly lossy. Only one video track and one audio track are kept; extra audio tracks and subtitles are left out.
• A width or height that is an odd number of pixels is trimmed by one pixel, because video encoders need even sizes.
• HDR video (for example from a recent iPhone) is converted to normal SDR colors, and 10-bit video becomes 8-bit, so it plays everywhere.
• Files up to 150 MB are accepted. Long or very high-resolution videos can take several minutes, and a conversion that runs past about 4 minutes is stopped with a message.