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Drop in the file
WAV or FLAC masters up to 1GB. MP3, M4A, AIFF and OGG are recognised too, with an explanation of why stores want lossless instead.
Drop in your master and catch the rejections before a store does: format, sample rate, bit depth, channels, clipping and edge silence, checked in seconds.
This check catches the most common reasons audio gets rejected, not every rule. The full requirements we apply at Unchained are in our audio file requirements guide, and no automated check replaces listening to your master top to tail.
Runs in your browser. Your audio is read on your device and never uploaded.
WAV or FLAC masters up to 1GB. MP3, M4A, AIFF and OGG are recognised too, with an explanation of why stores want lossless instead.
The file is read and decoded on your device: format, stereo, bit depth and sample rate first, then the waveform itself for clipping, edge silence and length.
Red items would get the file rejected; yellow ones are worth fixing before upload. Re-render, drop it in again, and deliver when it reads green.
Most audio rejections are not about the music. They are mechanical: the wrong container, a mono bounce, a sample rate the pipeline does not take, a limiter set to zero leaving flat-topped clipping, or fifteen seconds of dead air someone forgot to trim from the render. Stores check these automatically, reject automatically, and the email rarely says which rule you broke.
This tool runs the same class of checks up front. It reads the file's real structure rather than trusting the extension, so a renamed MP3 does not pass as a WAV, and it decodes the audio to inspect the waveform itself: peak level, flat-topped sample runs, silence at the edges, and whether the file contains any signal at all.
The format rules matter more than they look. Lossy formats like MP3 and AAC throw audio away to shrink the file, and stores transcode every delivery again for streaming, so delivering lossy means paying the quality cost twice. WAV and FLAC carry the full master; FLAC just packs it smaller.
A clean pass here means the file will not bounce for the common mechanical reasons. It does not grade the master itself, so listen top to tail once more before you send it anywhere.
It checks WAV and FLAC fully, which are the formats accepted for distribution. MP3, M4A/AAC, OGG and AIFF files are recognised and explained: the fix is exporting WAV or FLAC from your original master.
Format and encoding, stereo versus mono, bit depth, sample rate and the combination of the two, clipping with peak level, silence at the start and end, whether the file is silent, and track length.
No. The file is read and decoded entirely on your device and never leaves it. Nothing is stored when you close the page.
16-bit files are accepted at 44.1 and 48 kHz only; 24-bit files are accepted up to 192 kHz. A 16-bit file at 96 kHz is a real rejection you can hit even though both numbers look professional on their own.
Runs of consecutive samples sitting at full scale, which is what a flat-topped waveform looks like in the data. A handful of runs can survive loud mastering; repeated runs mean the limiter ceiling needs lowering, commonly to around -1 dBFS.
More than 10 seconds of silence at the start or end is a rejection reason. Shorter overruns get a warning: the fix in every case is trimming the render.
No, and we are honest about that. This catches the mechanical rejection reasons: it cannot hear a bad mix. Listen to the master top to tail before delivering it.
Yes. Free to use, no account, nothing uploaded. It is one of a set of browser tools we build for artists and labels preparing releases.
Unchained delivers your music to 150+ platforms with royalty splits, playlist pitching and real support behind every release.