Changelog
What's new in Spectro
v1.4.1May 30, 2026
Large library stability
Fixes batch stalls when browsing scanned tracks during long sessions, plus more reliable spectrogram loading in libraries with hundreds of files.
Fixed
- Batch processing no longer stalls when browsing already-scanned tracks during a large scan
- Spectrograms load more reliably when switching between tracks in large libraries
- Move to Trash button works again for fake tracks in the list
Improved
- Selected track spectrograms get priority while batch analysis is running
- Faster recovery when cached spectrogram data is evicted during long sessions
v1.4.0May 29, 2026
Engine accuracy upgrade
Sharper verdicts for real-world edge cases, plus workflow upgrades for daily library cleaning.
New
- Search tracks within your current session
- Watch Folder support to auto-analyze new files dropped into a monitored folder
- Notifications when a batch scan completes
- Disable Finder tags option in Settings
- Analyze with Spectro from the Finder right-click menu
Fixed
- Clipping detection no longer reports clean on files affected by an end-of-file read edge case
- Duplicate frequency-related labels in the diagnostics panel
Improved
- Verdict Engine v1.4 adds crest factor, clipping detection, and stereo correlation signals in diagnostics
- Adaptive spectral threshold calibrates cutoff detection to each file's energy profile
- Classical and piano recordings are less likely to be misclassified in the medium zone
- Borderline 19-20 kHz files get more precise verdicts using high-band density analysis
- 44.1 to 48 kHz upsample patterns are detected more reliably
v1.3.1May 24, 2026
Bug fix & UI improvements
Fixes a crash when navigating tracks with arrow keys on macOS 26 Tahoe, plus general UI improvements.
Fixed
- Crash when navigating tracks with arrow keys on macOS 26 Tahoe
Improved
- General UI improvements
v1.3.0May 22, 2026
DJ Workflow Update — our biggest update yet
Rekordbox import, M3U playlists, ALAC support, CSV export, spectrogram window, library stats, and more.
New
- ALAC support — Apple Lossless files (.m4a) are now analyzed correctly, including bit depth detection
- Import library from Rekordbox XML — scan your entire collection without dragging files manually
- M3U/M3U8 playlist import and export — load playlists directly and export your analyzed batch as a playlist
- CSV report export — export your full batch with verdict, format, bitrate, cutoff, and confidence columns
- Spectrogram window — open any track's spectrogram in a full-size resizable window
- Export spectrogram as PNG — save a high-resolution image of any spectrogram with verdict watermark
- Library stats — the empty state now shows your historical LOSSLESS %, FAKE %, upscaled count, and last analyzed date
- Show in Finder — reveal any track in Finder directly from the results list
- Redesigned File and Export menus — all import and export actions now in one place
Improved
- Peak spectrum analysis — dual mean+peak algorithm reduces false positives on classical and acoustic recordings
- Clipping detection — second-pass analysis catches more edge cases
- Bit-depth upscaling detection — identifies 16-bit audio masquerading in 24-bit containers
- FAKE verdict now shows the vendor/encoder string as supporting evidence
- Verdict panel redesigned — cleaner layout, clearer diagnostic bullets
- Onboarding redesigned — faster to understand, highlights Rekordbox support
v1.2.0May 8, 2026
Sharper spectrograms
Keyboard navigation, clickable drop zone, sharper spectrograms, and smarter detection for lossless files.
New
- Keyboard navigation: use ← → arrow keys to move between tracks without clicking
- Click to browse: the drop zone is now clickable; no need to drag if you prefer the file picker
- Report a Bug: new option in the Help menu
Fixed
- Certain FLAC files from Soulseek and non-standard encoders failed to analyze
- Hi-res files (192 kHz) showing as "Possible transcode" when correctly detected as upsampled; message now reads "Hi-res container, standard-res content"
Improved
- Sharper spectrograms: the silence zone above the cutoff is now deeper black, making fake files easier to spot at a glance
- Colored cutoff line: the frequency cutoff marker now turns red for FAKE and yellow for MEDIUM, matching the verdict badge
- Confidence score for 48 kHz lossless files was showing lower than expected; corrected
- Detection threshold for WAV and AIFF files tightened: fewer missed fakes in lossless containers
v1.1.1May 5, 2026
AAC support & onboarding
AAC files now supported, a new welcome screen on first launch, and more evidence shown when a fake file is detected.
New
- AAC files (.aac) can now be analyzed alongside FLAC, WAV, AIFF, and MP3
- Welcome screen on first launch: a quick walkthrough of how spectrograms work, what the verdicts mean, and how Finder tags are applied
- When a file is flagged as FAKE, the encoder name is now shown as supporting evidence (e.g. "Encoder: LAME 3.99.5") so you can see exactly what compressed the audio
Fixed
- Filter labels were clipped at small window sizes
- Dropped files were added to the bottom of the list instead of the top
Improved
- MP3, M4A and AAC files can no longer return a LOSSLESS verdict; the format itself is lossy, so the result now reflects that clearly
v1.1.0Apr 27, 2026
Detection accuracy & auto-updates
Three detection fixes for real-world edge cases, trial limit raised to 100 tracks, and automatic updates so you're always on the latest version.
New
- Automatic updates: Spectro now checks for new versions and installs them in the background without leaving the app
Fixed
- Broadcast and radio library tracks at 32 kHz were incorrectly flagged as FAKE; Spectro now checks the cutoff against the file's actual sample rate, not a fixed threshold
- MP3 files renamed to .wav or .aiff were passing as lossless; Spectro now detects the original encoder from the file header regardless of extension
- Files at 319-320 kbps were showing "~256 kbps" in the diagnosis panel; the bitrate label now reads from the file's metadata directly
Improved
- Free trial raised from 10 to 100 tracks, enough to scan a full DJ set before deciding
- The diagnosis panel now flags files in the high-bitrate ambiguous zone (256 kbps / VBR-0) where spectral analysis alone cannot give a definitive answer
v1.0.0Apr 20, 2026
Initial release
First public release of Spectro: fake lossless detector for macOS.
New
- FFT spectral analysis with heatmap visualization
- Batch scan: analyze entire folders at once
- LOSSLESS / FAKE / MEDIUM verdict with confidence score
- Drag & Drop from Finder
- Fully offline: no internet required for analysis
- License activation via Lemon Squeezy (2 Mac license)
- Requires macOS 13 Ventura or later