Compare WebM Video and Advanced Systems Format formats — understand the key differences and when to use each
WebM Video
WebM is an open-source video format developed by Google, specifically designed for efficient web video delivery. WebM uses the VP8 or VP9 video codec (or the newer AV1) with Vorbis or Opus audio, providing excellent quality at small file sizes. VP9 delivers quality comparable to H.265/HEVC while being royalty-free. WebM is natively supported by all major web browsers (Chrome, Firefox, Safari, Edge) and is the preferred format for YouTube's adaptive streaming. The format supports transparent video (alpha channel), HDR, and 4K+ resolutions. WebM's open-source, royalty-free nature makes it attractive for web developers and content creators who want to avoid licensing fees associated with H.264/H.265.
Advanced Systems Format
Advanced Systems Format (.asf) is a video file format.
| Feature | WEBM | ASF |
|---|---|---|
| Full Name | WebM Video | Advanced Systems Format |
| File Extension | .webm | .asf |
| Category | video | video |
| Free to Convert | ✓ Yes | ✓ Yes |
| Browser Support | ✓ All Browsers | ✓ All Browsers |
| Convert to Each Other | ✓ Yes | ✓ Yes |
またはファイルをここにドラッグ＆ドロップ
最大ファイルサイズ：2GB