Internet music dealers currently sell "CD-Quality" tracks, or even better ("Studio-Master"), thanks to lossless audio coding formats (FLAC, ALAC). However, a lossless format does not guarantee that the audio content is what it seems to be. The audio signal may have been upscaled (increasing the resolution), upsampled (increasing the sampling rate) or even transcoded from a lossy to a lossless format. Lossless Audio Checker analyzes lossless audio tracks and detects upscaling, upsampling and transcoding (only for AAC in this early version).

Our goal is to raise awareness on these bad practices from the music industry and pressure them to deliver true lossless music. Help us by testing your music and reporting your results — it's free!

AES paper

Lossless Audio Checker 2.0 was presented on October 30th, 2015 at the 139th Audio Engineering Society (AES) Convention in New York. More information about our paper is available here.


Platform Arch. GUI v2.0.6 (Regular users) CLI v2.0.5 (Power users)
Windows 64-bit Lossless-Audio-Checker-Windows-64bit.zip LAC-Windows-64bit.zip
32-bit Lossless-Audio-Checker-Windows-32bit.zip LAC-Windows-32bit.zip
macOS 64-bit - LAC-macOS-64bit.zip
Linux 64-bit - LAC-Linux-64bit.tar.gz
32-bit - LAC-Linux-32bit.tar.gz
Changelog Changelog-GUI.md Changelog-CLI.md