Lossy Transcode Detector
Inspect spectral holes and cutoff patterns that may indicate prior lossy encoding. Results are heuristic, not proof of provenance.
What this tool tells you
What it does
Use this when a lossless container raises questions about possible earlier lossy encoding and you want to inspect signal evidence locally.
How to use it
Open a WAV, FLAC, or AIFF file and review the spectral-hole and cutoff findings together with the reported file information.
How to interpret it
The findings describe evidence consistent with prior lossy encoding, not a complete file history. Filtering, mastering choices, codec settings, and the source can produce similar patterns.
Frequently Asked Questions
- What is a lossy transcode?
- A lossy transcode can occur when audio previously encoded with a lossy format, such as MP3, is later stored in a lossless container, such as FLAC. Container metadata alone cannot establish that history.
- How does the detector assess possible lossy ancestry?
- It analyzes spectral holes and frequency-cutoff patterns for evidence consistent with prior lossy encoding. Those patterns are heuristic and can have other causes, so they do not prove a file’s complete history.
Selected files are processed locally in the browser and are not uploaded to TrueRes for processing. Open this page in a modern browser to use the interactive tool.