Video to WebM
Transcode video to VP9/Opus WebM.
Add video
MP4, MOV, WebM, MKV, AVI — up to 2 GB per file.
Choose an output
Transcode video to VP9/Opus WebM.
Fine-tune
Optional — sensible defaults are already set.
About Video to WebM
WebM is an open video format built for the web. This tool encodes your video with the VP9 codec and Opus audio, which usually gives smaller files than H.264 at similar quality and plays natively in Chrome, Firefox, Edge and recent Safari.
When it helps
- Preparing a background or hero video for a website where file size affects page load.
- Making short clips for platforms or chat apps that prefer WebM, such as Discord or some forum software.
- Creating open-format copies of videos for projects that avoid patent-encumbered codecs.
Tips
- VP9 is much slower to encode than H.264, and in the browser that difference is very noticeable. Expect a long wait for anything more than a few minutes of HD video.
- The quality slider still controls the result: the tool adds a small offset to the value because VP9's CRF scale differs from H.264's. Move it left for more detail and bigger files.
- If the video needs to play in old Safari versions, on older smart TVs or in desktop editors, an MP4 is the safer choice.
Good to know
Quick answers about video to webm in your browser.
For web delivery, VP9 WebM is often smaller at the same visual quality. MP4 with H.264 has wider device and editor support. Many websites serve WebM with an MP4 fallback.
Yes. This tool encodes the audio as Opus, which is efficient and well suited to both speech and music.
Yes. There is no sign-up, no watermark and no limit on how many files you process.
No. Files are read and processed locally in your browser, so they never leave your device.
Large files are slow in WebAssembly and must stay under 2GB.
Related tools
Part of the Video Converter collection.