- Is my video uploaded anywhere?
- No. The conversion runs inside your browser tab. The page reads the MP4 from your disk in small pieces, decodes the audio with your browser's built-in media decoder, and writes the WAV on your device. Open your browser's network tab while it runs and you'll see the video isn't sent anywhere. That's also why there's no upload wait — a 1 GB video starts converting the moment you click.
- Should I pick WAV or MP3?
- Pick WAV when the audio is going into an editor, a transcription service, or a sampler — anything that will process it further. WAV stores every sample as a plain number with no compression, so each edit and export starts from the full decoded signal instead of stacking another round of lossy compression on top. Pick MP3 when you just want to listen, share, or save space: a 4-minute song is about 45 MB as a 16-bit WAV and about 6 MB as a 192 kbps MP3.
- Which bit depth should I choose?
- 16-bit is CD quality and opens in every player, phone, car stereo, and editor — use it unless you have a reason not to. 24-bit is the standard in audio editors and DAWs; it gives you more room when you raise quiet parts or add effects, and the file is 50% bigger. 32-bit float stores samples as decimals, so levels that go above full scale while editing aren't clipped; it doubles the size of 16-bit and a few older players can't open it. The audio inside an MP4 is almost always compressed AAC, so a higher bit depth won't add detail that the video never had — it only gives your editing more headroom.
- How big will the WAV be?
- WAV size is exact arithmetic, not a guess: sample rate × channels × bytes per sample × seconds, plus a 44-byte header. For 48 kHz stereo — the usual video audio — that's about 11 MB per minute at 16-bit, 16 MB at 24-bit, and 22 MB at 32-bit float. A 4-minute music video comes out around 45 MB at 16-bit; a 1-hour mono lecture at 44.1 kHz and 24-bit is about 454 MB. The tool shows the size before you convert. Tags copied from the video, like the title, add a few bytes.
- Why is the WAV so much bigger than the video?
- Because the video stores its audio compressed and the WAV doesn't. AAC audio in an MP4 usually runs at 128–256 kbps. A 16-bit, 48 kHz stereo WAV is 1,536 kbps — six to twelve times more data for the same seconds of sound. That's the trade: WAV files are big, but every program can read them instantly and editing them never costs quality.
- What's the biggest file I can convert?
- The video can be up to 4 GB and 3 hours long, and the WAV it makes has to fit in 2 GB. The finished WAV is held in your browser's memory until you download it, and 2 GB is the most we ask a tab to carry. Three hours of 48 kHz stereo at 16-bit is 1.9 GB, so it fits. At 24-bit or 32-bit float, long videos can pass the limit — the tool tells you before converting and suggests 16-bit or splitting the video. On phones and older laptops, closing other tabs helps big conversions finish.
- Does the WAV keep the original sample rate and channels?
- The sample rate stays exactly as it was in the video — 48 kHz stays 48 kHz, 44.1 kHz stays 44.1 kHz — so nothing is resampled. Mono stays mono and stereo stays stereo. Surround tracks (5.1 and 7.1) are mixed down to stereo, because multichannel WAV files open inconsistently across players and editors. If the video has no sound track at all, the tool tells you right away instead of making a silent WAV.
- It says my browser can't decode the audio. What now?
- The conversion uses your browser's built-in audio decoder. Update to the current Chrome, Edge, Firefox, or Safari and try again. If it still fails, the video may use an unusual audio format — some cameras and newer phones record spatial or lossless audio that browsers can't decode yet. Exporting the video again with standard AAC audio fixes it.
