Audacity is a free and open-source digital audio editor and recording application software, available for Windows, macOS, Linux, and other Unix-like operating systems.

[6][7] The project was started in the fall of 1999 by Dominic Mazzoni and Roger Dannenberg at Carnegie Mellon University, initially under the name CMU Visual Audio.

[9] Over the years, additional volunteer contributors emerged, including James Crook who started the fork DarkAudacity to experiment with a new look and other UX changes.

[13] In April 2021, it was announced that Muse Group (owners of MuseScore and Ultimate Guitar) would acquire the Audacity trademark and continue to develop the application, which remains free and open source.

For a long time, non-destructive editing was exclusive to volume envelopes[20] and playback rates, but since version 3, this has been extended to clip trimming[21] and effects.

[22] Audacity natively imports and exports WAV, AIFF, MP3, Ogg Vorbis, and all file formats supported by libsndfile library.

Due to patent licensing concerns, the FFmpeg library necessary to import and export proprietary formats such as M4A (AAC) and WMA is not bundled with Audacity but has to be downloaded separately.

[35] It also has a large array of digital effects and plug-ins,[36] including: noise reduction based on sampling the noise to be minimized,[37] vocal reduction and isolation for creation of karaoke tracks and isolated vocal tracks,[38] a wide range of effects like reverb, echo, and equalization,[39] pitch adjustment maintaining speed, and speed adjustment maintaining pitch.

[43] In addition to English, Audacity is available in Afrikaans, Arabic, Basque, Bulgarian, Catalan, Chinese (simplified), Chinese (traditional), Corsican, Czech, Danish, Dutch, Finnish, French, Galician, German, Greek, Hungarian, Irish, Italian, Japanese, Lithuanian, Macedonian, Marathi, Norwegian (Bokmål), Polish, Portuguese (Brazilian), Romanian, Russian, Slovak, Slovenian, Spanish, Swedish, Turkish, Ukrainian, Vietnamese and Welsh.

As free and open-source software, Audacity is very popular in education, encouraging its developers to make the user interface easier for students and teachers.

[47][48] Jamie Lendino of PC Magazine recently rated it 4/5 stars Excellent and said: "If you're looking to get started in podcasting or recording music, it's tough to go wrong with Audacity.

[60] That July, the Audacity team apologized for the changes to the privacy policy and removed mention of the data storage provision which was added "out of an abundance of caution".