Convert WEBA to CAF — Free Online Tool
Convert WEBA audio files (WebM audio containers using Opus or Vorbis encoding) to CAF, Apple's Core Audio Format, using PCM uncompressed audio for maximum compatibility with macOS and iOS workflows. This tool runs entirely in your browser — no uploads, no server, just instant conversion powered by FFmpeg.wasm.
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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.
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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 store compressed audio using the Opus or Vorbis codec inside a WebM container — a format optimized for browser-based streaming and web playback. CAF (Core Audio Format) is Apple's professional-grade container, and this conversion decodes the compressed Opus or Vorbis stream from the WEBA file and re-encodes it as uncompressed PCM (16-bit signed little-endian) audio inside the CAF container. This is a full decode-and-re-encode operation, not a remux, because the codecs differ: Opus/Vorbis is lossy and compressed, while pcm_s16le is raw, uncompressed audio. The result is a lossless-representation CAF file suitable for Apple Logic Pro, GarageBand, Core Audio APIs, or any macOS/iOS audio pipeline. Note that since the original WEBA source was lossy, the CAF output captures the decoded quality of the source — it will not recover detail lost during the original Opus/Vorbis encoding.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg program, the open-source multimedia processing engine that handles all decoding, codec conversion, and container remuxing. In the browser-based tool, this runs as FFmpeg.wasm compiled to WebAssembly. |
-i input.weba
|
Specifies the input file — a WEBA audio file, which is a WebM container holding Opus or Vorbis compressed audio. FFmpeg reads the container, identifies the audio stream and its codec, and prepares it for decoding. |
-c:a pcm_s16le
|
Sets the output audio codec to PCM signed 16-bit little-endian, which is raw uncompressed audio. This decodes the Opus or Vorbis stream from the WEBA source and writes it as full-fidelity uncompressed PCM — the format expected by Apple Core Audio APIs and natively supported by GarageBand and Logic Pro inside a CAF container. |
-b:a 128k
|
Specifies a target audio bitrate of 128 kbps. For PCM audio (the codec used here), this flag has no practical effect since uncompressed PCM does not use bitrate-based compression — output size is determined by sample rate and bit depth. This flag would only become meaningful if switching to a compressed codec like AAC within the CAF container. |
output.caf
|
Defines the output filename and, through the .caf extension, instructs FFmpeg to use the Core Audio Format container. CAF is Apple's professional audio container designed to support large file sizes and a wide range of codecs, making it the native audio format for macOS and iOS development and production workflows. |
Common Use Cases
- Bringing web-recorded audio (e.g., from a browser-based voice memo or WebRTC call saved as WEBA) into GarageBand or Logic Pro on macOS for editing or mixing
- Preparing audio captured from a web app for use in an iOS development project that uses Core Audio or AVFoundation APIs, which natively favor CAF files
- Converting a WEBA podcast recording or interview saved from a browser tool into an uncompressed CAF file to serve as a clean master before further processing or compression
- Migrating audio assets from a web-based production workflow (where WEBA is common) into an Apple-ecosystem post-production pipeline that expects CAF input
- Archiving decoded Opus or Vorbis web audio as uncompressed PCM in CAF to avoid generational quality loss from repeated lossy re-compression in future editing sessions
- Supplying audio to macOS command-line tools or frameworks like afconvert or afplay that operate natively on CAF files
Frequently Asked Questions
No — the conversion decodes the lossy Opus or Vorbis audio from the WEBA file into uncompressed PCM, but it cannot restore detail that was discarded when the WEBA file was originally encoded. The output CAF file will be an accurate, uncompressed representation of what the WEBA file contained, but its true quality ceiling is still determined by the original Opus/Vorbis encoding bitrate. Think of it as uncompressing a JPEG into a TIFF — the file is now lossless in format, but the original compression artifacts remain.
WEBA files store audio using Opus or Vorbis compression, which can achieve high-quality audio at bitrates as low as 96–128 kbps. The output CAF file uses pcm_s16le — raw, uncompressed 16-bit audio — which for stereo audio at 44.1 kHz consumes roughly 10 MB per minute, regardless of the original content. This size increase is expected and is the nature of converting from a compressed lossy format to an uncompressed PCM format.
Yes — CAF is Apple's own container format and is natively supported across the Apple ecosystem, including QuickTime Player, GarageBand, Logic Pro, Final Cut Pro, and Core Audio APIs on both macOS and iOS. The pcm_s16le codec used in this conversion is one of the most universally supported audio encodings on Apple platforms, making the output CAF file broadly usable without any additional plugins or conversion steps.
WEBA (WebM audio) supports limited metadata through the Matroska/WebM tagging system, and CAF uses its own distinct metadata structure. FFmpeg will attempt to map compatible tags during conversion, but metadata support in CAF is minimal compared to formats like MP3 or M4A, and not all WEBA tags will transfer cleanly. If metadata preservation is critical, you should verify the output file in a tool like MediaInfo or Apple's afinfo after conversion.
Because the output codec is pcm_s16le (uncompressed PCM), the -b:a bitrate flag in the command does not meaningfully control file size or quality — PCM audio is always stored at full uncompressed fidelity, and its size is determined by sample rate and bit depth rather than a bitrate setting. If you want a compressed CAF output at a specific bitrate, you would need to change the codec, for example to AAC with -c:a aac -b:a 192k. However, for Apple ecosystem workflows, uncompressed PCM in CAF is typically preferred as an intermediate or master format.
Yes — this page displays the exact FFmpeg command used by the browser tool, and you can copy and run it on any desktop machine with FFmpeg installed. The browser-based tool supports files up to 1GB for free, but if your WEBA file exceeds that limit, running ffmpeg -i input.weba -c:a pcm_s16le -b:a 128k output.caf directly in your terminal will handle files of any size. FFmpeg is available for free on macOS via Homebrew (brew install ffmpeg), Windows, and Linux.
Technical Notes
The core operation in this conversion is decoding a lossy-compressed Opus or Vorbis audio stream (extracted from the WebM/WEBA container) and writing it as PCM signed 16-bit little-endian audio into a CAF container. pcm_s16le provides a 96 dB dynamic range and is the default PCM variant chosen by FFmpeg for CAF output — it is universally readable on Apple hardware and software. If your source WEBA file was encoded at a low bitrate (e.g., 64k), the decoded PCM will faithfully represent that compressed audio, meaning quantization noise and frequency roll-off from the original Opus encoding will be present in the CAF output. WEBA does not support multiple audio tracks, subtitles, or chapters, so there are no stream-selection concerns during this conversion. CAF supports very large file sizes without the 4GB limitation of WAV or AIFF, making it suitable for long-form audio such as film soundtracks or podcast archives. One practical limitation: CAF files are not broadly supported outside the Apple ecosystem — they are not natively playable on Windows or Android without third-party software, so this output format is best used as a production intermediate on Apple platforms rather than a distribution format.