Playproof converts the tracks your gear can't play, repairs the files that fail for no obvious reason, and flags the FLACs that are secretly MP3s. It runs in your browser. Your music never leaves your machine.
The track is right there on the stick. The deck can see it. It just won't load it, and nothing tells you why.
Usually it's the WAV. A lot of them carry 32-bit float samples, or a
format tag called WAVE_FORMAT_EXTENSIBLE instead of plain
PCM. Bandcamp downloads do this. So do most DAW exports. No CDJ will
touch either one. Playproof rewrites the header and the file plays.
A CDJ-2000NXS plays MP3, AAC, WAV and AIFF. That's the whole list. If your library is FLAC or ALAC, none of it works, and plenty of clubs still run those decks.
Point Playproof at your folder and pick what you're playing on. It converts what needs converting and leaves the rest alone.
Someone converted a lossy file to FLAC. It's the right size, the right extension, and it sounds fine on laptop speakers. On a club system it doesn't.
Playproof looks at the spectrum of every track it touches. A lossy encoder throws away everything above a cutoff, and that cutoff survives being rewrapped. So the fake ones show up as a hard shelf where real music keeps going.
Every other checker uses a threshold. That's why they flag half your records: an old recording or a dark master looks exactly like a transcode to a fixed rule.
Playproof measures each track against the rest of your library. If everything you own rolls off at 18 kHz, that's how you like your music and nothing gets flagged. If one track in a clean folder shelves at 16 kHz, that's the one worth listening to.
Pick your gear and Playproof applies its rules. Sample rate ceilings, accepted formats, folder depth, filename limits.
CDJ-2000 · CDJ-2000NXS · CDJ-900 · CDJ-850 · CDJ-350 · XDJ-700
No FLAC, no ALAC. Everything lossless is converted.
CDJ-3000 · CDJ-3000X · CDJ-2000NXS2 · XDJ-1000MK2 · XDJ-XZ
Reads FLAC and ALAC. Broken WAV headers still get repaired.
SC6000 · SC5000 · PRIME 4 · PRIME GO
Reads almost everything. Mostly a verification pass.
Most pre-2015 and budget head units · older Pioneer, Kenwood, Sony, Alpine
MP3 only, numbered filenames so tracks play in order, flat folders.
Reads MP3, AAC, M4A, FLAC, ALAC, WAV, AIFF, Ogg and Opus. Writes MP3, WAV and AIFF. Tags, cover art, BPM and key all come across.
This isn't a promise, it's how the thing is built. Conversion happens in your browser using your own CPU. There's no server to send files to.
The app is allowed to contact exactly one address, and only when you enter a licence key. You can check that yourself: open developer tools and read the content security policy, or read the source, which is public.
Chrome, Edge or Brave to write straight to a USB stick. Firefox and Safari can't give a website access to a folder, so there you pick files and get a ZIP instead.
No. It reads your music and writes converted copies to the folder you choose. Nothing in the source folder is touched.
Converting to AIFF or WAV runs at roughly a hundred times real time, so 500 tracks is around twenty minutes. MP3 is slower because the encoder is doing real work: budget an hour and a half for the same 500. If it gets interrupted, nothing is lost. Run it again and it picks up where it stopped.
Different job. OneLibrary carries cue points, beatgrids and playlists between recent gear from AlphaTheta, Native Instruments and Algoriddim. It doesn't convert audio. If your deck can't read FLAC, OneLibrary doesn't change that.
It might be wrong. A dark master or an old recording can look like a transcode to the maths. Treat the list as tracks worth listening to rather than a verdict, and send the file over if you think the call is bad.
Yes. Paste it again. It doesn't expire and there's no device limit.
Free for 25 tracks. No account, no email address.
Open the app