Is it really lossless?

Drop a FLAC, WAV or ALAC file. If it was ever an mp3, the encoder left a cliff in its spectrum — and the cliff survives conversion back to a lossless container.

Drop audio files or a folder here

or click to choose — flac, wav, m4a, mp3, ogg

Choose files

Everything runs in your browser. Your files are never uploaded anywhere.

Examples

Table 1Batch audit

Only suspect & likely

#	File	Verdict	cutoff	likely source	analysed

Click a row to open its full report below.

Is it really lossless?

Drop audio files or a folder here

Table 1Batch audit

§ 1Findings

Fig. 1Long-term spectrum

Fig. 2Spectrogram

§ 2How it decides

§ 3Reading the spectrogram