Convert MP4 to WAV
Get an uncompressed WAV from any MP4, for audio editors, transcription or archiving. Made on your device.
- Nothing is uploaded
- Works offline after first use
- Open source
- No sign-up, no watermark. The limit is your device’s memory (phones hold less).
Extract the audio from an MP4 as an uncompressed WAV file in your browser, ready for editing or transcription. It is free, needs no account and adds no watermark, and your files are not uploaded: everything runs in your browser on your device. The limit is your device’s memory, which is smaller on a phone, and after your first run the page works offline.
Your iPhone may take a few seconds to prepare the video first, longer if it's stored in iCloud.
Done
Free, no ads. Support StayPut
Open the network tab. Your files never appear in it.
Add files and run the tool to see every request this tab makes.
Your files are processed on this device and never sent to a server. Reload the page to clear everything from memory.
WAV is what audio software expects. Editors such as Audacity, Premiere and Logic, transcription and subtitling tools, and speech-analysis services often ask for WAV because it is uncompressed: every sample is stored as is, with nothing to decode and no further loss when you cut, mix or process it. Converting an MP4 to WAV gives you the video’s sound track in that form.
This page opens with WAV selected. Your browser decodes the MP4’s audio track and the page writes a standard 16-bit, 44.1 kHz PCM WAV, stereo or mono. Nothing is re-compressed, so the WAV holds exactly what the decoder produced. Expect about 10 MB per minute in stereo and half that in mono.
Because WAVs are large, a server-based converter has to push them back down to you as well as receive the video. Here both directions disappear: the MP4 is read from your disk and the WAV is written to it, and the recording never exists anywhere else.
How it works
- Drop one or more MP4 files, or tap to pick them.
- WAV is already chosen. Pick mono if the recording is a single voice, to halve the size.
- Convert. The WAV downloads; several come as a zip.
In your browser, not on a server
Your browser decodes the sound track with the same audio decoders it uses to play media on any website (AAC for MP4, MOV and M4A; Opus or Vorbis for WebM; FLAC, WAV and MP3). The samples are resampled to 44.1 kHz and handed to LAME, the reference MP3 encoder, compiled to WebAssembly and served by this site. WAV files are written directly by a few lines of code in the page. A WMA, which no browser plays, is decoded in a background worker by a separately loaded decoder module. Most video runs on your browser's WebCodecs through Mediabunny. For old formats the browser cannot read, the page loads a decoder built from FFmpeg's libraries (LGPL) only when you convert such a file. Everything happens in memory in your tab.
Compared with upload-based tools: Online converters upload the whole video just to keep its sound, cap free files at a few hundred megabytes, and make you wait in a queue. Home videos, lectures and voice memos are personal. Here the file never leaves your device, so a 1 GB video converts as fast as your computer can read it, and the limit is your device’s memory (phones hold less).
Verify it yourself. Give the page a short while after your first run to save itself for offline use, then turn off Wi-Fi or switch to airplane mode and run the tool again. Or open your browser's developer tools (F12, or Cmd-Option-I on a Mac), pick the Network tab, and watch it while you convert. The panel above does the same count for you.
Questions
Is the WAV better quality than the MP4’s audio?
It is exactly as good, no better. The MP4’s AAC audio is decoded once and stored uncompressed, so nothing more is lost, but detail removed when the MP4 was made cannot come back.
What sample rate and bit depth is the WAV?
44.1 kHz, 16-bit PCM, the CD standard every audio program opens. Audio recorded at 48 kHz is resampled to 44.1 kHz.
Can I get an MP3 instead?
Yes. Change the output format to MP3 on this page, or use the MP4 to MP3 page, which opens with MP3 at 192 kbps.
The WAV is too big. How do I make it smaller?
Tick mono if the recording is a single voice: that halves the size. For a much smaller file, run the WAV through Compress WAV, which saves it as an MP3 or OGG and can fit it under a size limit.
Is the file uploaded anywhere?
No. There is no server in this process. The page is a static file and the work is done by code running inside your browser tab. Give the page a short while after your first run to save itself for offline use; then you can turn off Wi-Fi and it still works.
More video and audio tools
Video to MP3
Pull the sound out of a video, or turn any audio file into an MP3. Your files are converted on this device and never uploaded.
GIF to MP4
Turn animated GIFs into small MP4 videos that post and play anywhere. Converted on this device, never uploaded.
Compress video
Make a video a fraction of the size, or fit it under a limit like 10 MB for Discord or 25 MB for email. It is compressed on this device and never uploaded.
Video to MP4
Turn MOV, MKV and WebM files into MP4s that play everywhere. Converted on this device, never uploaded.
Other conversions
Guides
- How to convert a video to MP3This is different from muting a video: you want the sound saved as its own file. Most devices have no built-in way to do that.
- Is FreeConvert safe?Yes: FreeConvert.com is a legitimate converter with a clear deletion policy, and fine for everyday files. Whether it is safe for a particular file depends on whether that file should be uploaded anywhere.
- Is Convertio safe?Convertio is a well-known converter with a published deletion policy. For private files, the safer choice is a converter that never receives them.
- Is Zamzar safe?Zamzar is one of the oldest online converters. Its storage window is longer than most, which is the detail worth knowing.
- A free CloudConvert alternative for everyday filesCloudConvert measures its free tier in credits tied to conversion time, not files, which makes it hard to predict when you will hit the limit. Here is an alternative with nothing to meter.