Extract Audio from WebM to AIFF — Free Online Tool
Extract audio from WebM files and save it as a lossless AIFF file using uncompressed PCM audio. This tool discards the VP9 video stream and decodes the Opus or Vorbis audio track into raw 16-bit big-endian PCM, giving you a pristine, uncompressed copy of the audio in a format widely supported by macOS and professional audio software.
to
FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
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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
WebM files typically carry audio encoded with Opus or Vorbis — both of which are lossy compressed codecs optimized for web streaming. During this conversion, FFmpeg strips the VP9 video stream entirely and decodes whichever audio codec is present (Opus or Vorbis) into uncompressed PCM audio. That PCM data is then written into an AIFF container using the pcm_s16be codec, which stores 16-bit signed samples in big-endian byte order — the native format Apple defined for AIFF. Because Opus and Vorbis are lossy, the AIFF output is not a lossless reconstruction of original studio audio; it is a lossless capture of what the lossy codec preserved. The file size will grow substantially compared to the WebM source because PCM audio is uncompressed.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg command-line tool, which handles all the demuxing, decoding, and encoding steps needed to extract audio from the WebM container and write it as an AIFF file. |
-i input.webm
|
Specifies the input WebM file. FFmpeg reads the Matroska-based container, identifies the VP9 video stream and the Opus or Vorbis audio stream, and makes both available for further processing. |
-vn
|
Disables video output entirely, discarding the VP9 video stream from the WebM file so that only the audio track is processed and written to the AIFF output. |
-c:a pcm_s16be
|
Decodes the WebM's Opus or Vorbis audio and re-encodes it as 16-bit signed big-endian PCM, which is the standard uncompressed audio codec for the AIFF format and is natively compatible with macOS and Apple audio software. |
output.aiff
|
Sets the output filename and tells FFmpeg to write an AIFF container. FFmpeg infers the AIFF format from the .aiff file extension and packages the pcm_s16be audio data accordingly. |
Common Use Cases
- Import a WebM screencast or tutorial recording into GarageBand or Logic Pro X, which natively open AIFF files without requiring plugins or intermediate conversion steps.
- Preserve a podcast or voiceover recording that was delivered as a WebM file in an uncompressed archival format before applying noise reduction or mastering in a professional DAW.
- Extract the audio from a WebM video downloaded from a web platform to use as a sample or loop in Ableton Live or Pro Tools, both of which handle AIFF natively.
- Convert a WebM conference call or meeting recording to AIFF so that a transcription service or audio editor on macOS can ingest it without codec compatibility issues.
- Prepare audio from a WebM animation or motion graphics file for a sound designer who needs an uncompressed AIFF stem to work with in post-production.
- Archive the audio track from a WebM video stored in an HTML5 web application into a format that will remain readable on macOS systems for years without depending on web-specific codecs like Opus.
Frequently Asked Questions
No. WebM uses Opus or Vorbis, both of which are lossy codecs, meaning some audio detail is permanently discarded during encoding. Converting to AIFF does not recover that lost information — it simply stores whatever the lossy codec preserved in an uncompressed PCM format. The AIFF will be a perfect lossless copy of the decoded WebM audio, but it will not exceed the quality ceiling imposed by the original lossy compression.
AIFF stores audio as raw, uncompressed PCM samples — 16 bits per sample at the full sample rate, with no compression applied. WebM with Opus or Vorbis achieves very small file sizes precisely because those codecs compress audio aggressively. A WebM file encoded at 128 kbps might expand to ten times or more its original size when stored as uncompressed 16-bit AIFF, depending on the sample rate and duration.
WebM stores metadata using Matroska-style tags, while AIFF uses its own chunk-based metadata format. FFmpeg makes a best effort to map common tags like title and artist, but not all WebM metadata fields have direct AIFF equivalents, and some tags may be dropped during conversion. If metadata preservation is critical, verify the output file's tags in a tool like MediaInfo or a macOS-compatible audio tagger after conversion.
By default, FFmpeg selects the first audio track in the WebM file, which is typically the default or primary language track. AIFF does not support multiple audio tracks in a single file, so only one track can be extracted per conversion. If you need a different track, you can modify the FFmpeg command with a stream specifier such as '-map 0:a:1' to select the second audio track explicitly.
The command uses '-c:a pcm_s16be', which produces 16-bit big-endian PCM — the standard AIFF bit depth. To get 24-bit output, replace 'pcm_s16be' with 'pcm_s24be', or use 'pcm_s32be' for 32-bit integer. For floating-point PCM, 'pcm_f32be' or 'pcm_f64be' are also valid AIFF codecs. Higher bit depths increase file size further but do not recover quality lost by the original Opus or Vorbis encoding.
Yes. On macOS or Linux, you can run a shell loop to process all WebM files in a directory: 'for f in *.webm; do ffmpeg -i "$f" -vn -c:a pcm_s16be "${f%.webm}.aiff"; done'. On Windows Command Prompt, the equivalent is 'for %f in (*.webm) do ffmpeg -i "%f" -vn -c:a pcm_s16be "%~nf.aiff"'. This applies the same extraction and PCM encoding to every file, which is especially useful when processing files larger than 1GB that exceed the browser tool's size limit.
Technical Notes
AIFF's pcm_s16be codec stores samples as 16-bit signed integers in big-endian byte order, which reflects AIFF's Motorola/Apple heritage and distinguishes it from WAV's little-endian PCM. The sample rate of the output AIFF will match whatever sample rate the WebM's audio stream carries — commonly 48000 Hz for Opus (Opus natively operates at 48 kHz) or 44100 Hz for Vorbis. No sample rate conversion is applied by default, so if your downstream tool expects 44100 Hz, you may need to add '-ar 44100' to the command when the source uses Opus. WebM files can technically contain multiple audio tracks and subtitle streams, but AIFF supports none of these: only a single stereo or mono audio stream is written to the output. Chapter markers and any embedded thumbnail or cover art present in the WebM container will also be discarded, as AIFF has no provision for them. Because the conversion involves fully decoding the Opus or Vorbis bitstream before writing uncompressed PCM, it is more CPU-intensive than a simple remux, though processing time is still generally fast relative to video transcoding.