Convert WEBA to ALAC — Free Online Tool
Convert WEBA audio files (WebM audio containers with Opus or Vorbis encoding) to ALAC, Apple's lossless audio format stored in an M4A/MPEG-4 container. This tool decodes the lossy WEBA source and re-encodes it into a lossless ALAC file fully compatible with iTunes, Apple Music, and all Apple devices.
to
FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
Drop your WEBA file here
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Free — no uploads, no signups. Your files never leave your browser.
Settings
Note: Browser-based encoding uses approximate quality targets. For precise CRF compression, copy the FFmpeg command above and run it on your desktop.
Estimated output:
Conversion Complete!
DownloadHow It Works
WEBA files use lossy compression — typically Opus or Vorbis codecs — which permanently discard audio data to achieve small file sizes. Converting to ALAC requires fully decoding the compressed WEBA audio stream back to raw PCM, then re-encoding that PCM data using Apple's lossless algorithm. The resulting ALAC file preserves the decoded audio with zero further quality loss, but it cannot recover the original data discarded during the initial lossy encoding. The output is wrapped in an MPEG-4 container (.m4a), which ALAC requires and which supports chapter markers and rich metadata tagging — features the WEBA format does not offer.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg tool — in this browser-based context, FFmpeg.wasm runs the same FFmpeg engine entirely within your browser using WebAssembly, with no server upload. |
-i input.weba
|
Specifies the input WEBA file. FFmpeg detects the WebM container and identifies the audio codec (Opus or Vorbis) automatically, preparing it for full decoding before re-encoding as ALAC. |
-c:a alac
|
Sets the audio codec to ALAC (Apple Lossless Audio Codec). This instructs FFmpeg to decode the lossy Opus or Vorbis audio from the WEBA source and re-encode it losslessly using Apple's ALAC algorithm, producing output compatible with iTunes, Apple Music, and all Apple devices. |
-c:a alac
|
A duplicate of the preceding audio codec flag — this second instance is redundant and has no additional effect. FFmpeg honors the last occurrence, so ALAC remains the selected codec. You can omit this flag when running the command locally without changing the output. |
output.m4a
|
Defines the output filename with an .m4a extension, which signals FFmpeg to use the MPEG-4 container — the required wrapper format for ALAC audio. The .m4a extension ensures correct recognition by Apple software and compatible players. |
Common Use Cases
- Archiving web-sourced audio content captured as WEBA (e.g., from browser recordings or WebRTC sessions) into a lossless format suitable for long-term storage in an Apple ecosystem library
- Importing WEBA audio clips into GarageBand or Logic Pro, which prefer ALAC or other Apple-native formats for project assets
- Adding WEBA podcast or voice recordings to an iTunes or Apple Music library where ALAC is the preferred lossless format for organization and playback
- Converting WEBA game audio or sound effect assets to ALAC for use in iOS or macOS app development projects
- Preparing WEBA web audio samples for distribution on Apple platforms where Opus codec support is limited but ALAC playback is natively guaranteed
- Standardizing a mixed audio archive that contains WEBA files alongside other formats into a single lossless ALAC collection for consistent Apple device playback
Frequently Asked Questions
No. WEBA uses lossy compression (Opus or Vorbis), which permanently discards audio information during the original encoding. Converting to ALAC is lossless from this point forward — no further quality is lost — but the quality ceiling is set by the original WEBA encoding. The ALAC file will be a lossless copy of what the decoded WEBA audio sounds like, not a restoration of pre-compression quality.
WEBA uses aggressive lossy compression (Opus at 64–320 kbps) to keep file sizes very small. ALAC stores a mathematically lossless representation of the decoded PCM audio, which requires substantially more space — typically 3 to 6 times the size of a comparable lossy file. This size increase is expected and reflects the lossless nature of ALAC rather than any inefficiency in the conversion.
WEBA files can carry basic Vorbis comment metadata, but support is inconsistent across tools and the tags may not transfer cleanly during conversion. The MPEG-4 container used by ALAC supports rich metadata tagging (title, artist, album, artwork, etc.), so after conversion you can use iTunes, Apple Music, or a tag editor like MusicBrainz Picard to add or correct tags. It is worth verifying and completing metadata manually after the conversion.
ALAC has been open-sourced by Apple and is supported beyond the Apple ecosystem. VLC, foobar2000, and many Android devices with the right app can play ALAC files. However, native support on non-Apple hardware and streaming platforms is less universal than formats like FLAC, so if cross-platform compatibility is a priority, FLAC may be a better lossless target.
The FFmpeg command shown includes '-c:a alac' twice, which is redundant but harmless — FFmpeg simply applies the last valid value for each option, so the audio codec is set to ALAC once. This does not affect the output in any way. If you are running the command locally, you can safely remove one instance: 'ffmpeg -i input.weba -c:a alac output.m4a'.
Yes. On Linux or macOS, you can use a shell loop: 'for f in *.weba; do ffmpeg -i "$f" -c:a alac "${f%.weba}.m4a"; done'. On Windows Command Prompt, use: 'for %f in (*.weba) do ffmpeg -i "%f" -c:a alac "%~nf.m4a"'. This processes each WEBA file individually and outputs a corresponding ALAC M4A file, which is necessary because ALAC does not support batch muxing multiple streams into one file.
Technical Notes
WEBA is an audio-only WebM container, most commonly carrying Opus audio (standardized by IETF for low-latency and streaming scenarios) or the older Vorbis codec. Neither Opus nor Vorbis is natively supported inside an MPEG-4 container, so direct stream copying is impossible — the audio must be fully decoded and re-encoded as ALAC. FFmpeg's built-in 'alac' encoder handles this cleanly without requiring any external libraries. The output .m4a file uses the MPEG-4 container, which ALAC requires and which supports chapter markers (a feature absent in WEBA). One known limitation is that ALAC does not support multichannel layouts beyond 8 channels, though this is rarely a concern for WEBA sources, which typically carry stereo or mono audio. If the WEBA source contains Vorbis audio rather than Opus, FFmpeg handles both transparently with the same command. Bit depth of the output ALAC defaults to 16-bit unless the decoded PCM source signals otherwise.