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Supports: WEBM
.webm clips. Batch conversion is supported, and each file gets the same settings.WebM is Google's open container, released May 2010 at Google I/O, that pairs VP8/VP9 (or AV1) video with Vorbis or Opus audio. AIFC — also written AIFF-C — is Apple's compressed extension of AIFF, finalised in August 1991 to add codec slots and a "COMM" chunk to the original 1988 spec. Converting a WebM (typically Opus-in-Matroska) to AIFC strips the video track and rewraps the audio in a container that older Mac apps, Logic Pro sessions, and broadcast workflows treat as a first-class citizen.
| Property | WebM | AIFC (.aifc) |
|---|---|---|
| Type | Video + audio container | Audio-only container |
| Owner / year | Google, May 2010 | Apple, August 1991 (extends AIFF 1988) |
| Container base | Matroska subset | IFF / EA 85 chunked file |
| Typical audio codecs | Opus, Vorbis | PCM (NONE/sowt), A-law, μ-law, fl32/fl64, MACE, IMA ADPCM |
| Compression | Lossy (Opus/Vorbis) | Lossless (PCM) or lossy (G.711, MACE) — codec dependent |
| Byte order | Little-endian (EBML) | Big-endian by default (NONE); little-endian via sowt |
| Native browser playback | Chrome, Firefox, Edge, Safari 14.1+ | None — desktop apps only |
| Common home | Web video, screen recordings | Logic Pro, Pro Tools, QuickTime, archival |
| Metadata | Matroska tags | NAME / AUTH / ANNO / (c) chunks, plus loop/instrument chunks |
| Codec (FourCC) | Compression | Typical use | Notes |
|---|---|---|---|
| PCM big-endian (NONE) | None — lossless | Default; DAW import, CD mastering | 16/24-bit, identical bit depth to AIFF |
| PCM little-endian (sowt) | None — lossless | Faster decode on Intel/Apple Silicon | Bit-for-bit equivalent to NONE |
| IEEE float 32 (fl32) | None — lossless | Mix bus / mastering with headroom | 32-bit floating-point samples |
| A-law (alaw) | ~2:1 lossy | EU PBX, SIP, IVR prompts | 8000 Hz mono, G.711 ITU-T |
| μ-law (ulaw) | ~2:1 lossy | North America / Japan telephony | 8000 Hz mono, G.711 ITU-T |
| MACE 3:1 / 6:1 | Lossy | Legacy Mac OS Classic apps | Obsolete; avoid for new work |
| IMA 4:1 ADPCM | ~4:1 lossy | Older QuickTime samples | Limited modern support |
Most modern workflows pick PCM (NONE) — it's lossless, decodes everywhere AIFF does, and gives you the .aifc extension some legacy importers require. Use G.711 only when targeting telephony gear.
Effectively none for the audio data — both store the same 16/24-bit PCM samples. The .aifc wrapper just declares an FVER (format version) chunk and a compression-type tag in the COMM chunk (set to "NONE" for big-endian PCM, "sowt" for little-endian). Some DAWs and archival systems insist on the .aifc extension when any compression slot exists; choose AIFC if your downstream tool requires it, otherwise convert WebM to AIFF and skip the FVER chunk.
Opus is lossy; PCM AIFC is lossless. The conversion is a one-way decode: Opus → PCM samples → AIFC container. You're not adding fidelity that wasn't there, but you're preserving every bit Opus reconstructed. If you pick A-law or μ-law inside AIFC you'll lose more quality on top — those codecs were designed for 3.4 kHz speech, not music.
AIFC was designed in 1991 to add codec slots to AIFF so Apple could distribute compressed samples for QuickTime, HyperCard, and System 7 multimedia titles when disk space was scarce. The compression options (MACE, IMA, G.711) are mostly historical now — the format is used today almost exclusively as a PCM container with the .aifc extension required by certain importers.
Match your source unless you need a specific target. WebM Opus is internally 48000 Hz, so leaving Sample Rate on Original gives you 48000 Hz output. Choose 44100 Hz for CD mastering, 48000 Hz for video post (Logic, Pro Tools, Premiere), or 8000 Hz mono for telephony. Bit depth defaults to 16-bit; pick higher when your DAW operates at 24-bit and you want headroom for further processing.
Yes. Many WebM files from OBS, browser MediaRecorder, or yt-dlp -x extraction contain only an Opus audio stream. The converter detects the audio track and ignores the (missing) video. If your WebM has both, the video is discarded — there's no equivalent inside AIFC.
Yes. Expand Advanced Options → Trim and enter a start time (HH:MM:SS.mmm) plus a duration. Only the requested segment is decoded and written to AIFC, which is faster than converting the full file and trimming after.
Yes — AIFC is part of the AIFF family Apple defined for these tools. Logic, Pro Tools (all versions), Final Cut Pro, and GarageBand recognise the .aifc extension and read the COMM chunk to identify the codec. For maximum compatibility with non-Apple DAWs (Reaper, Ableton, Cubase, FL Studio), use PCM (NONE) inside AIFC or convert to WAV instead.
WebM Opus typically runs 64–192 kbps; uncompressed 16-bit/44.1 kHz stereo PCM is 1411 kbps — about 10 MB per minute. A 5-minute Opus track at 128 kbps (5 MB) becomes ~50 MB as PCM AIFC. That's the cost of lossless. If size matters more than fidelity, pick μ-law/A-law inside AIFC or convert to MP3 instead.
Files are processed in your browser session and not retained — there's no account, no watermark, and conversion artefacts stay tied to your session. Batch a folder of WebM screen recordings without worrying about leaks of confidential content.