Convert WebM to MKV on Mac
Convert WebM files to MKV format on your Mac with Jollycat. Open web video format by Google using VP8/VP9 video and Vorbis/Opus audio. Optimized for web streaming. All processing runs locally on your Mac — no cloud processing and no uploads required for conversion.
WebM vs MKV
| Property | WebM | MKV |
|---|---|---|
| Type | container | container |
| Compression | VP8/VP9 + Vorbis/Opus | Any codec |
| Container | Yes | Yes |
| Common Codecs | VP8, VP9, AV1, Vorbis, Opus | H.264, H.265, VP9, AV1, FLAC, AAC, DTS |
| File Extension | .webm | .mkv |
| Key Advantage | Royalty-free | Supports any codec |
How to Convert WebM to MKV on Mac
Open your WEBM file
Drag and drop your .webm file onto the Jollycat icon in your macOS dock or menu bar. Jollycat instantly detects the format.
Choose MKV as output
Select MKV from the conversion options. Adjust quality settings, bitrate, or resolution if needed.
Convert and save
Click Convert and Jollycat processes the file instantly on your Mac. No uploads required, no waiting — everything runs locally on Apple Silicon.
When to Convert WebM to MKV
MKV advantages
Supports any codec. Multiple audio/subtitle tracks.
WebM limitations
No Safari/Apple support. Limited hardware acceleration.
Common use cases
High-quality video storage, Movies with subtitles, Multi-track media.
WebM to MKV Conversion Tips
Use Jollycat's trim and crop tools to edit your video before converting. This saves time by only processing the parts you need.
For sharing online, MKV with H.264 codec provides the best balance of quality and compatibility.
MKV is a flexible container that can hold virtually any video, audio, and subtitle codec combination.
Frequently Asked Questions
Is the WebM to MKV conversion free?
Jollycat is a one-time purchase for $9.99. Once purchased, you can convert WebM to MKV and use all 1,650+ conversion paths with no limits.
Does converting WebM to MKV require an internet connection?
No. Jollycat processes everything locally on your Mac. Your WebM files never leave your device — all conversion happens offline using Apple Silicon.
Can I batch convert multiple WebM files to MKV?
Yes. Drag multiple WebM files onto Jollycat and convert them all to MKV at once. Batch processing is built in.
Ready to Convert WebM to MKV?
Jollycat handles WebM to MKV conversion and 1,650+ other format conversions. All offline on your Mac.
Get Jollycat for Mac