Audacity

Audacity is the audio editor everyone starts with — and many professionals never leave. Free and open-source for over two decades, it records anything, cuts and arranges waveforms with precision, and cleans up recordings with noise reduction, click removal, and vocal isolation.

Podcasters edit episodes in it, musicians demo ideas, and archivists digitize tapes. The effects catalog covers the essentials — EQ, compression, reverb, pitch — and plugins extend it further. Spectrogram views reveal problems your ears only suspected.

The interface won’t win design awards, and its flexibility demands a little learning. But as free audio capability goes, nothing else comes close on any operating system.