Convert QT to WebM — Free Online Converter
Convert QuickTime (.qt) to WebM Video (.webm) online for free. Fast, secure video conversion with no watermarks or registration.
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安全な転送
HTTPS暗号化アップロード
プライバシー優先
処理後にファイルを自動削除
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すぐに変換を開始
どこでも動作
あらゆるブラウザ、あらゆるデバイス
変換方法
Upload your .mov file by dragging it into the upload area or clicking to browse.
Choose your output settings. The default settings work great for most files.
Click Convert and download your .webm file when it's ready.
MOVからWebMへの変換について
WebM is Google's open, royalty-free multimedia format specifically designed for the web. It pairs VP8 or VP9 video with Vorbis or Opus audio in a Matroska-based container. VP9, the recommended video codec, achieves quality comparable to H.264 while remaining completely patent-free. Converting QuickTime files to WebM produces web-optimized video that plays natively in Chrome, Firefox, Edge, and Opera without any plugins or licenses.
MOVをWebMに変換する理由
QT files don't play in web browsers and require QuickTime Plugin (long deprecated) or transcoding. WebM is one of the two formats universally supported in HTML5 video (alongside MP4). For open-source web projects, WebM avoids H.264's patent licensing obligations. Google also optimizes YouTube's internal processing for VP9/WebM.
主な活用例
- Embedding QT video on websites using HTML5 video elements
- Uploading QT content to platforms that prefer VP9 encoding (YouTube, Google services)
- Creating web video from QT sources for open-source web applications
- Publishing QT content on blogs and portfolios with browser-native playback
- Preparing QT video for WebRTC-based video conferencing platforms
仕組み
FFmpeg encodes QT video to VP9 using libvpx-vp9 with two-pass encoding for optimal quality distribution. Audio is encoded to Opus at 128 kbps (or Vorbis for older browser compatibility). The WebM/Matroska container uses a cues element at the file start for fast seeking. VP9 encoding uses CRF 31 with the 'good' quality deadline for a practical speed/quality balance.
品質とパフォーマンス
VP9 at CRF 31 produces quality comparable to H.264 at CRF 23 — the codecs use different CRF scales. The output is visually excellent for web delivery. VP9's efficiency advantage over VP8 and H.264 is most pronounced at lower bitrates and higher resolutions.
デバイス互換性
| Device | MOV | WebM |
|---|---|---|
| Windows PC | Partial | Partial |
| macOS | Partial | Partial |
| iPhone/iPad | Partial | Partial |
| Android | Partial | Native |
| Linux | Partial | Native |
| Web Browser | No | Native |
プラットフォーム別の推奨設定
YouTube
Resolution: 1920x1080
Bitrate: 8-12 Mbps
H.264 recommended for fast processing
Resolution: 1080x1080
Bitrate: 3.5 Mbps
Square or 9:16 for Reels
TikTok
Resolution: 1080x1920
Bitrate: 4 Mbps
9:16 vertical, under 60s ideal
Twitter/X
Resolution: 1280x720
Bitrate: 5 Mbps
Under 140s, 512MB max
Resolution: 960x540
Bitrate: 2 Mbps
16MB limit for standard, 64MB for document
Discord
Resolution: 1280x720
Bitrate: 4 Mbps
8MB free, 50MB Nitro
最良の結果を得るためのヒント
- 1Use two-pass encoding for VP9 — it significantly improves quality consistency across scenes compared to single-pass CRF mode.
- 2Set the CRF to 31 for web video (equivalent to H.264 CRF 23) and adjust from there based on quality needs.
- 3Provide both WebM and MP4 sources in HTML5 video elements for maximum browser compatibility.
- 4For 4K web video, VP9 is strongly preferred over H.264 — the file size savings are most dramatic at higher resolutions.
- 5Enable Opus audio at 128 kbps for the best audio quality-to-size ratio in WebM.
関連する変換
QT to WebM conversion produces web-native, patent-free video with excellent quality. It's the ideal format for open-source web publishing and provides efficient compression for Google's web ecosystem.
MOVとWebMの比較
| 特徴 | MOV | WebM |
|---|---|---|
| 正式名称 | Apple QuickTime Movie | WebM Video |
| 拡張子 | .mov | .webm |
| 最適な用途 | High quality | Web optimized |