Convert WebM to ALAC — Free Online Converter
Convert WebM Video (.webm) to Apple Lossless Audio Codec (.alac) online for free. Fast, secure video conversion with no watermarks or registration....
200万以上のファイル変換
数千人のユーザーに信頼されています
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
登録不要
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 .webm 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 .m4a file when it's ready.
About WebM to ALAC Conversion
WebM files contain Opus or Vorbis audio — high-quality open-source lossy codecs. ALAC (Apple Lossless Audio Codec) is Apple's lossless compression format, open-sourced in 2011, that compresses PCM to 50-60% size with zero data loss. ALAC integrates natively with Apple Music, iTunes, iPhone, iPad, and the entire Apple ecosystem.
Why Convert WebM to ALAC?
Extracting WebM audio to ALAC creates a lossless archival copy that integrates perfectly with Apple devices. The ALAC output serves as a master from which any future lossy format (AAC, MP3) can be derived without cascading generation losses. This is valuable when building Apple Music libraries from web audio sources.
ALAC is also the format that displays the 'Lossless' badge in Apple Music, adding perceived quality to imported web audio.
Common Use Cases
- Building Apple Music libraries from YouTube/WebM audio in lossless quality
- Creating archival audio masters from WebM web content for the Apple ecosystem
- Extracting podcast audio from WebM for lossless storage on iCloud Drive
- Building lossless reference copies from WebM sources for future format conversions
- Importing web audio into Apple Music with the Lossless quality badge
How It Works
FFmpeg decodes the WebM container's Opus or Vorbis audio to raw PCM, then encodes using the ALAC encoder into an M4A container. Output at 16-bit/44.1 kHz or 16-bit/48 kHz (matching the source). Compression achieves 50-60% of PCM size. The M4A container supports full iTunes-compatible metadata.
Quality & Performance
ALAC losslessly preserves every decoded sample. Since the source is lossy (Opus/Vorbis), the ALAC output contains the same quality — no better, no worse. The advantage is preventing further loss during future operations.
Device Compatibility
| Device | WebM | ALAC |
|---|---|---|
| Windows PC | Partial | Partial |
| macOS | Partial | Native |
| iPhone/iPad | Partial | Native |
| Android | Native | Partial |
| Linux | Partial | Partial |
| Web Browser | Native | No |
Recommended Settings by Platform
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
Tips for Best Results
- 1Match the source sample rate — keep 48 kHz for Opus sources rather than downsampling
- 2Use ALAC as a master copy and derive AAC versions for portable devices
- 3Add rich metadata for polished Apple Music library entries
- 4For cross-platform needs, also create a FLAC copy alongside ALAC
- 5Tag accurately to note the source was WebM Opus/Vorbis for reference
Related Conversions
WebM to ALAC provides the ideal Apple-native archival format for decoded web audio, with lossless preservation and seamless ecosystem integration.