Convert WebM Video (.webm) to MPEG-4 Audio (.m4a) online for free. Fast, secure video conversion with no watermarks or registration.
Conversion settings — add a file to adjust
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.
WebM files contain Opus or Vorbis audio — open-source codecs with excellent quality. M4A is Apple's audio-only MPEG-4 container, holding AAC or ALAC audio. M4A is the native format for Apple Music, iTunes, iPhone Voice Memos, and the entire Apple ecosystem, supporting rich metadata including album art, lyrics, and chapter markers.
M4A integrates seamlessly with every Apple device and service. While Opus is technically superior to AAC, the iPhone's Music app cannot play Opus natively, and Apple Music does not accept Opus imports. M4A with AAC provides the closest quality match to Opus in Apple's native format.
For YouTube audio downloads (served as Opus in WebM), converting to M4A produces files that integrate perfectly into Apple Music libraries.
FFmpeg extracts Opus or Vorbis from the WebM container, decodes to PCM, and re-encodes to AAC-LC or ALAC in the M4A container. For AAC, the native or libfdk_aac encoder is used. Opus at 48 kHz can be kept at 48 kHz or resampled to 44.1 kHz. M4A supports full iTunes-compatible metadata.
AAC at 256 kbps in M4A provides excellent quality from Opus/Vorbis sources. The lossy-to-lossy generation loss is minimal at adequate bitrates. ALAC output preserves the decoded audio losslessly for archival purposes.
| Device | WebM | M4A |
|---|---|---|
| Windows PC | Partial | Partial |
| macOS | Partial | Native |
| iPhone/iPad | Partial | Native |
| Android | Native | Partial |
| Linux | Partial | Partial |
| Web Browser | Native |
Resolution: 1920x1080
Bitrate: 8-12 Mbps
H.264 recommended for fast processing
Resolution: 1080x1080
Bitrate: 3.5 Mbps
Square or 9:16 for Reels
Resolution: 1080x1920
Bitrate: 4 Mbps
9:16 vertical, under 60s ideal
Resolution: 1280x720
Bitrate: 5 Mbps
Under 140s, 512MB max
Resolution: 960x540
Bitrate: 2 Mbps
16MB limit for standard, 64MB for document
Resolution: 1280x720
Bitrate: 4 Mbps
WebM to M4A provides the cleanest path from web audio to Apple's native ecosystem with full metadata and device integration.
Truyền tải an toàn
Tải lên được mã hóa HTTPS
Quyền riêng tư là ưu tiên
Tệp tự động xóa sau khi xử lý
Không cần đăng ký
Bắt đầu chuyển đổi ngay lập tức
Hoạt động mọi nơi
| No |
8MB free, 50MB Nitro
Mọi trình duyệt, mọi thiết bị
| Tính năng | WebM | M4A |
|---|---|---|
| Tên đầy đủ | WebM Video | MPEG-4 Audio |
| Phần mở rộng | .webm | .m4a |
| Phù hợp nhất cho | Web optimized | Better than MP3 |