How to rip audio from an mp4 as wav or flac (lossless)
- Step 1Open the extractor — Load audio-track-extractor. FFmpeg.wasm initialises in-browser; after the first load it's cached. Your file is never uploaded.
- Step 2Drop the source video — Add one MP4, MOV, MKV, WebM, or AVI. For lossless work the source audio matters most — the extractor preserves whatever fidelity the source track has; it can't add detail that isn't there.
- Step 3Pick WAV for editing or FLAC for archive — In the Audio output panel's Format dropdown choose WAV (16-bit PCM, biggest, max compatibility) or FLAC (lossless, ~half the size). Choose based on whether you're editing now or storing for later.
- Step 4Run the extraction — WAV runs
-vn -c:a pcm_s16le out.wav; FLAC runs-vn -c:a flac out.flac. Both decode the source and re-encode losslessly into the new container — one pass, no signal loss. - Step 5Save the master — On Chromium the file can stream straight to a chosen folder; elsewhere it downloads as
<name>.wavor<name>.flac. WAV files of long sources are large — make sure you have disk room. - Step 6Take it into your workflow — Import the WAV/FLAC into your DAW or restoration tool. Need a small portable copy too? Re-run with MP3 output. Cleaning podcast audio? See the podcast guide.
WAV vs FLAC — the two lossless paths
Both formats preserve the complete source signal. The difference is container, size, and compatibility, not fidelity.
| Attribute | WAV | FLAC |
|---|---|---|
| FFmpeg args | -vn -c:a pcm_s16le | -vn -c:a flac |
| Lossless? | Yes (uncompressed PCM) | Yes (compressed) |
| Typical size (stereo 44.1 kHz) | ~10 MB/min | ~4–6 MB/min |
| Compatibility | Universal — every editor | Excellent, occasionally needs a plugin |
| Bit depth | 16-bit (pcm_s16le) | Preserves decoded depth |
| Best for | Active editing / mastering | Long-term archive masters |
Lossless vs lossy: when to pick what
All five formats share one extractor. These are the trade-offs for choosing a lossless path over a portable one.
| Goal | Format | Why |
|---|---|---|
| Edit / master the audio | WAV | Uncompressed PCM, opens everywhere |
| Archive a master, save space | FLAC | Lossless, ~half the size of WAV |
| Bit-identical copy of AAC source | AAC | Only stream-copy path (-c:a copy) |
| Portable file for phone/sharing | MP3 | 192 kbps, universally playable |
| Discord voice message | Opus | 128 kbps Opus, the platform format |
Cookbook
Real lossless-extract jobs. Sizes assume stereo 44.1 kHz unless noted; your numbers vary with channels and sample rate.
MP4 interview to a WAV editing master
A recorded interview (MP4, AAC audio) needs to go into a DAW for noise reduction. WAV gives an uncompressed PCM master the DAW handles natively.
Source: interview-raw.mp4 (AAC 256 kbps) Format: WAV Command: ffmpeg -i interview-raw.mp4 -vn -c:a pcm_s16le interview-raw.wav Result: interview-raw.wav (16-bit PCM) Note: this decodes the lossy AAC then writes lossless PCM — it can't recover detail AAC discarded, but adds no new loss.
Live recording MKV to FLAC archive
A long live set captured to MKV. You want a lossless archive that doesn't eat disk like WAV would. FLAC is the answer.
Source: liveset-2026.mkv (2 h, FLAC or PCM audio) Format: FLAC Command: ffmpeg -i liveset-2026.mkv -vn -c:a flac liveset-2026.flac Result: liveset-2026.flac WAV equivalent would be ~1.2 GB; FLAC ~500–700 MB, same signal.
WAV from a source that already holds PCM
If the MKV's audio is already PCM, WAV is still a re-encode into the WAV container (not a copy) — but it's lossless, so the audio is unchanged.
Source: field-recording.mkv (pcm_s16le audio) Format: WAV Result: field-recording.wav (pcm_s16le) WAV/FLAC are never stream-copy; AAC is the only -c:a copy path.
Choosing FLAC to halve archive size
You have 50 lecture recordings to archive losslessly. FLAC over WAV roughly halves total storage with zero quality difference.
Per file (60 min stereo): WAV ~600 MB FLAC ~250–350 MB 50 files: WAV ~30 GB vs FLAC ~15 GB — same audio, half the disk.
When NOT to use WAV/FLAC
If your only goal is a perfect untouched copy of an AAC track, WAV/FLAC re-encode (losslessly, but they still rebuild the stream). For a literal byte-copy, AAC is the correct choice.
Goal: untouched copy of an AAC stream WAV: decodes + re-encodes to PCM (lossless, but rebuilt) FLAC: decodes + re-encodes to FLAC (lossless, but rebuilt) AAC: ffmpeg ... -vn -c:a copy out.aac <- true stream-copy See /video-tools/solutions/convert-video-soundtrack-to-aac-no-loss
Edge cases and what actually happens
WAV/FLAC are not stream-copy
By designUnlike AAC, choosing WAV or FLAC always decodes the source audio and re-encodes it (pcm_s16le / flac). Both are lossless, so there's no generation loss — but the engine does real work, not a fast remux. If you specifically want a byte-identical copy, the source is AAC and AAC is the format to pick.
Re-encoding lossy source to WAV doesn't restore quality
ExpectedExtracting WAV/FLAC from an MP4 whose audio is lossy AAC gives you a lossless container around a lossy signal. It preserves exactly what's there but cannot recover detail AAC already discarded. The WAV is 'lossless' relative to the decoded source, not relative to the original studio recording.
WAV file is very large
ExpectedUncompressed PCM runs ~10 MB/minute for stereo 44.1 kHz, so a 2-hour source is well over 1 GB. That can collide with the Free-tier 1 GB cap on the way out and will need disk space. Choose FLAC (roughly half) or upgrade for big masters.
WAV 4 GB size limit on extremely long sources
LimitedThe classic WAV container uses 32-bit size fields, so PCM WAV files approach a ~4 GB practical ceiling on very long recordings. For multi-hour high-sample-rate captures, FLAC sidesteps this entirely and is the safer archive choice.
Bit depth is fixed at 16-bit
By designWAV output uses pcm_s16le — 16-bit PCM. There is no 24-bit or 32-float option in the dropdown. For most extracted soundtracks (already 16-bit or lossy) this is transparent; true 24-bit mastering pipelines should source from the original session, not a re-extracted file.
Source has no audio track
FailsA silent screen recording or timelapse has no audio stream; -vn removes the video and there's nothing for pcm_s16le/flac to encode, so FFmpeg exits with an error. Verify the source has sound before extracting.
Only the default audio track is extracted
By designThere is no track-picker. The first/default audio stream is what gets extracted. A multi-stream MKV (e.g. stereo mix + 5.1 mix) yields only the default stream in the current build.
FLAC compression in WASM is CPU-bound
Slow but supportedFLAC encoding runs in browser WebAssembly, so long high-sample-rate sources take noticeably longer than native FFmpeg. The result is still bit-perfect lossless; just expect the encode to take a while for big files.
Frequently asked questions
Is the WAV/FLAC actually lossless?
Yes. WAV is uncompressed 16-bit PCM and FLAC is lossless compression — both carry the full signal of the decoded source with no quality loss introduced by the extraction. What they can't do is recover quality the source already lost (e.g. if the source audio was lossy AAC).
WAV or FLAC — which should I choose?
WAV for active editing (uncompressed, opens in every tool with zero friction). FLAC for archive (lossless but typically 40–60% smaller). The audio inside is identical; it's purely a size-versus-compatibility trade.
Does extracting WAV upload my file?
No. Everything runs in your browser via FFmpeg.wasm. Sensitive session recordings, unreleased music, and confidential interviews stay entirely on your machine — there is no server round-trip.
Can I get 24-bit WAV?
Not from this tool — WAV output is fixed at 16-bit PCM (pcm_s16le). For genuine 24-bit mastering you should work from the original recording session rather than a re-extracted file, since extraction can't add bit depth that the source track didn't carry.
Why is the WAV file so big?
Uncompressed PCM is roughly 10 MB per minute for stereo 44.1 kHz audio. A long source produces a large file and can approach the WAV ~4 GB practical ceiling. Use FLAC for long recordings — it's lossless and about half the size.
Is WAV a stream-copy of the source?
No. WAV (and FLAC) always decode the source audio and re-encode into the new container. That's lossless so there's no quality concern, but it's not a fast remux. The only stream-copy path in this tool is AAC, which works when the source audio is already AAC.
What source formats can I rip from?
MP4, MOV, MKV, WebM, AVI, M4V, and TS. The extractor drops the video with -vn and encodes the source audio to your chosen lossless format.
How long a video can I extract a master from?
There is no duration cap — only a file-size limit. Free tier allows 1 GB sources, Pro 10 GB, and Pro + Media 100 GB. For long sources, WAV size may be the binding constraint, so consider FLAC.
Can I extract a 5.1 surround track as WAV?
The extractor pulls the default audio stream and encodes it; it doesn't offer per-track selection or channel remapping. If the default stream is surround, the WAV will reflect that, but choosing between a stereo mix and a 5.1 mix in a multi-track file isn't supported yet.
Will FLAC keep the sample rate of the source?
The FLAC encode preserves the decoded source's sample rate and channels. It compresses losslessly without resampling, so the archive matches what the source delivered.
I need both a master and a portable copy — how?
Run the extractor twice: once with FLAC (or WAV) for the master, once with MP3 for the portable copy. Each run is independent and local.
Can this clean up noise or normalise loudness?
No — extraction is a clean demux/re-encode, not a mastering tool. For noise reduction and loudness work, take the lossless WAV/FLAC into a dedicated audio pipeline; the podcast workflow guide outlines that path.
Privacy first
Every JAD Video tool runs entirely in your browser via WebCodecs and FFmpeg (WebAssembly). Your video files never leave your device — verified by zero outbound network requests during processing.