Spectro

Spectro reads the actual frequency spectrum of each audio file, not the file extension, and returns a LOSSLESS, MEDIUM or FAKE verdict with the frequency cutoff where the signal was really cut off — catching MP3s that were upscaled and renamed to FLAC or WAV. It batch-scans whole folders, writes the verdict straight into Finder as a color tag, and can watch a folder to flag new files automatically. The method follows a peer-reviewed 2009 paper and claims 99% accuracy across 2,512 songs; the one case it calls genuinely ambiguous, 256 kbps CBR versus high-quality VBR, gets 92.4% accuracy, and Spectro says so instead of hiding it. Runs fully offline on macOS, one-time $24.99 for one Mac, with a 100-track free trial.