WebM
WebM is a media container associated with VP8/VP9/AV1 and Vorbis/Opus.
Common uses
- HTML5 video
- Some screen recordings
- Open web delivery
Strengths
- No H.264 licensing story
- Good compression with VP9/AV1
Weaknesses
- Patchy NLE export defaults
- Safari history of slower adoption
Compatibility. Current Chromium is comfortable. Safari support exists for many WebM streams now but should be tested.
Size and quality. Often competitive with MP4 at similar perceptual quality. Measure.
How to open it. A browser that can decode the codec inside. The extension is not enough.
How to convert it. Export from your editor. ConvertPass inspects; it does not transcode yet.
Security and privacy. Untrusted media. No execution.
Related tools
- Video file inspector
Read duration and resolution from a video without uploading it.
- Video bitrate calculator
Turn file size and duration into an estimated bitrate, locally.
Related comparisons
Last reviewed 16 August 2026.