SpectroFake lossless
track-04-master.flac
~128 kbps MP3 in a FLAC wrapper. Brick wall at 15.9 kHz. Only hiss above the line. You paid for nothing.
Fake lossless detector for macOS
Know which “lossless” tracks are really MP3s.
Scan WAV, AIFF, FLAC and ALAC files locally. Spectro checks the audio itself, not just the file extension, and gives every track a clear LOSSLESS, MEDIUM or FAKE verdict before you play it.
macOS 13+ · No account · Works offline · One-time purchase from $24.99
The problem.
A file extension is not proof.
The spectrogram shows what's actually inside.
Online stores, promo channels and Bandcamp uploads are full of MP3s upscaled and renamed to FLAC, WAV or AIFF. The file size goes up. The audio inside doesn't. Spectro reads the actual waveform with a full FFT, like a luthier tapping wood.
Real lossless
turbo-rosso-original.wav
Energy reaches the Nyquist ceiling at 22.3 kHz. Air, transients and shimmer survive intact. This is what you bought.
What's included.
Built for real DJ and audiophile libraries.
Spectro isn't a one-trick spectrogram viewer. It's a verdict engine, a batch scanner and a Finder-native quality control tool, tuned for libraries with tens of thousands of files.
A verdict per file.
Every track gets one answer: LOSSLESS, MEDIUM, or FAKE, with cutoff and a one-line diagnosis.
Batch-scan and export.
Scan an entire folder, get a verdict per track, and export spectrogram PNGs for multiple results in one batch.
Automatic Finder color tags.
Spectro writes color tags directly to your files. Open the folder later and problem files are already marked red.
100% on-device. Fully offline.
Audio never leaves your Mac. No cloud upload, no library telemetry, and no account required. Sandboxed and notarized.
One-time, from $24.99.
Personal for 1 Mac or Duo for 2. Same features on both plans, free updates, and no subscription or per-track fee.
Watch folders automatically.
Point Spectro at a folder and new tracks are analyzed automatically. Universal binary with Sparkle updates.
Works with your setup.
Works with your existing DJ workflow.
Import from Rekordbox XML or any M3U/M3U8 playlist, compatible with Traktor and VirtualDJ. Serato support coming soon.
SoonHow it works.
Three steps to check your files. No setup or re-import.
Spectro doesn't need to know about your music management app. Drop files, get verdicts, decide what to do with them.
Drop files or folders.
FLAC, WAV, AIFF, ALAC, MP3, AAC. A track, an album, or ~/Music. No import.
Drop a folder FLAC · WAV · AIFF
Or ~/Music No import
Get a verdict per file.
Spectral content, not the extension. Results stream in as they finish.
01 · Turbo Rosso.wavLOSSLESS
02 · Across The Sun.wavMEDIUM
03 · Vocoder.mp3FAKE
Act on what you find.
Filter FAKEs, move them to Trash, or open the spectrogram before you replace a track.
FilterFAKE (4)
Move to Trash⌫
Open spectrogram↵
Why you can trust the verdict.
Peer-reviewed fake lossless detection. Native and offline.
99% accuracy on transcoding detection,
across 2,512 songs.
Spectro's spectral analysis is built on the methodology of D'Alessandro & Shi's peer-reviewed paper on MP3 bit-rate quality detection. The only known ambiguous case (256 kbps CBR vs. high-quality VBR) gets 92.4% accuracy, which Spectro flags explicitly as MEDIUM in the diagnosis panel.
Your library never leaves your Mac.
Drop a folder, get verdicts. Spectro runs entirely on your machine: no internet required, no account to create, no files ever uploaded. Pull the network cable and it still works exactly the same.
- Works fully offline, no internet needed
- No account, no sign-up, no tracking
- Apple Silicon (M1–M4) + Intel
- Secure checkout via Lemon Squeezy; we never see your card
From the community.
What users found in their libraries.
Reddit · r/macappsView original ↗
“I loaded all 653 tracks from my 'lossless' library into it. 10 fake, 57 medium, 586 lossless. And it analyzed them quite quickly.”
Reddit · r/ProductHuntersView original ↗
“I've just bought my own copy after a few tests. It looks reliable. My FLAC library is now getting huge. About 20TB.”
Reddit · r/MacOSAppsView original ↗
“Spectro just works the way I actually was hoping others would work. Very glad I found this post before pulling the trigger on Fakin' the Funk.”
Pricing.
One-time purchase.
No subscription.
All features included. Choose the number of Macs.
Personal
For 1 Mac
$24.99
once · USD
Buy Personal · $24.99Best value
Duo
For 2 Macs
$39
once · USD
Buy Duo · $39Unlimited file scansOffline and privateFree updates30-day money-back
Want to try it first?Analyze 100 tracks free. No card required.
Frequently asked questions about Spectro.
What is fake lossless audio?
A fake lossless file is an MP3 or AAC that has been re-encoded and saved as WAV, AIFF or FLAC. The file size is larger but the audio quality is identical to the original compressed file - the high frequencies above the MP3 cutoff are permanently lost.
Can I import my Rekordbox library directly into Spectro?
Yes. Spectro supports Rekordbox XML import directly: go to File → Import from Rekordbox and select your Rekordbox XML export file. Spectro loads your full collection automatically, with no drag and drop required. To export your XML from Rekordbox: File → Export Collection in xml format.
Does Spectro support ALAC files?
Yes. Spectro 1.3 added full ALAC support. Apple Lossless files (.m4a) are analyzed the same way as WAV and FLAC: spectral content determines the verdict, not the container.
Will it work with Beatport and Bandcamp downloads?
Yes. Spectro processes files from any source: WAV, AIFF, FLAC, ALAC, MP3, and AAC.
Does it upload my files anywhere?
No. Spectro runs entirely on your Mac. Nothing is uploaded, no account is needed, and no internet connection is required for analysis.
How does the free trial work?
Spectro is free for your first 100 tracks. No time limit, no account required.
Can I export my scan results to CSV?
Yes. Use File → Export CSV to save your full batch results with verdict, format, bitrate, cutoff frequency, and confidence score for every track.
Can I export multiple spectrograms at once?
Yes. Spectro supports PNG export for individual spectrograms and bulk export for a batch of analyzed tracks.
What happens after I buy?
You receive a license key by email. Enter it in the app to unlock unlimited scans. Personal lets you activate Spectro on 1 Mac for $24.99; Duo supports up to 2 Macs for $39. Same features on both plans.
Use cases.
Choose your audio workflow.
Choose the guide that matches your setup. Each page is focused on one intent so you can move from search to trial quickly.
Free trial · 100 tracks · No card
Find out what's actually
in your library tonight.
Drop your most suspicious folder into Spectro and have your answer before the kettle boils.
macOS 13+ · Universal · No subscription · ever · 30-day refund