Spek

What Spek is

Spek analyzes audio files by displaying their spectrograms, giving you a way to inspect audio offline. It supports popular lossy and lossless formats through FFmpeg libraries and uses multiple processing threads to speed analysis. Alongside the spectrogram, it shows spectral density, the codec name, and audio signal parameters. You can adjust the spectral density range and save a spectrogram as an image. Time, frequency, and spectral density rulers fit automatically to the display, and the interface supports drag and drop and association with common audio formats.

Spek is free and open-source software under GPLv3, with no paid plans stated. It runs on Linux, macOS, and Windows and is translated into multiple languages. Version 0.8.5 is listed as the latest; the Windows and macOS installers are marked beta. The Windows installer supports 64-bit systems only. The macOS installer requires Catalina or newer and is built for Intel CPUs; the maker says it should work with newer ARM chips. Downloads also include a BSD/GNU/Linux source tarball and a Windows archive. The project accepts bug reports and feature requests through its GitHub issue tracker.