Convert WAV to FLAC
Halve the size of WAV recordings without losing a single sample, on your own device.
- Nothing is uploaded
- Works offline after first use
- Open source
- No watermark · limit is your device’s memory; phones hold less
Convert WAV to FLAC in your browser: the same sound at about half the size, sample rate kept. 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 size limit is your device’s memory, and phones hold less; give the page a short while after your first run to save itself for offline use, and then it works offline.
Done
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.
FLAC is lossless compression for audio: it stores exactly the same samples as a WAV, packed the way a zip packs a document, so the file is usually 40 to 60 percent smaller and decodes back to the identical sound. It keeps the sample rate, plays in most music apps and on Android, and is what music archives and download stores use.
This page reads each WAV from your disk and writes the FLAC in your browser, keeping the original sample rate. Nothing is uploaded, so a folder of multitrack stems or an hour of field recordings converts as fast as your computer can read it, and unreleased material stays on your machine.
A typical job is an archive of recordings: a folder of bounced mixes, a band's rehearsal takes or a field recorder's card. Drop the whole folder, leave FLAC and Stereo chosen, and you get a zip of FLAC files with the same names. The sample rate of each file is kept, so a 48 kHz recording stays 48 kHz and a 96 kHz one stays 96 kHz. The one change is depth: samples are written at 16 bits, so a 16-bit WAV comes back bit for bit, and a 24-bit or 32-bit float WAV does not.
Choose Mono only when both channels of the WAV are the same, for example a single microphone recorded into a stereo file. Then the FLAC is half the size again and loses nothing. For a real stereo recording, Mono mixes the two sides together, which you cannot undo. AIFF files from Logic or a Mac can be dropped here too and come out as FLAC in the same way.
How it works
- Drop one or more WAV files, or tap to pick them.
- FLAC is already chosen. Pick mono only for a voice recording.
- Convert. Each FLAC downloads when it is ready; several come as a zip.
In your browser, not on a server
Your browser decodes the sound with the decoders it uses to play media on any website. The new file is written in your tab: MP3 by LAME compiled to WebAssembly, WAV by a few lines of code, FLAC by a small lossless encoder in this site’s code (fixed predictors and Rice coding, as the FLAC format describes), and M4A or OGG by the browser’s own AAC and Opus encoders (WebCodecs), packed by Mediabunny (MPL-2.0). WAV and FLAC keep the original sample rate.
Compared with upload-based tools: Online audio converters upload every file, queue it, cap free use at a few files or a few hundred megabytes, and keep the upload for hours. Recordings of meetings, unreleased songs and voice memos are private. Here the files never leave your device and a whole folder converts at once.
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
How much smaller is the FLAC?
Usually 40 to 60 percent of the WAV for music, less for quiet speech and near silence, more for dense noise. The saving depends on the sound, not on a setting.
Is 24-bit kept?
No. The FLAC is 16-bit, like a CD. For 24-bit masters you will keep editing, keep the WAV.
How can I check the FLAC is really lossless?
For a 16-bit WAV, convert the FLAC back to WAV on this same page and compare the two in an audio editor: invert one and mix it with the other, and the result is silence. Command-line audio tools that print a checksum of the decoded samples show the same numbers for both files.
Will the FLAC play on my phone and in my music app?
Android, Windows, VLC, foobar2000 and most music players read FLAC. On an iPhone the Files app and VLC play it, but the Apple Music app does not import FLAC. If the files are going into an Apple library, convert a copy to M4A for listening and keep the FLAC as the archive.
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.
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Guides
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