Piriform

CCleaner was first launched in 2004 for Microsoft Windows. It remained a Windows-only utility until 2012. On 2 June 2011, Piriform announced a public beta test program for CCleaner for Mac. The Mac version graduated to the test stage on 30 January 2012.

A commercial Network Edition was also introduced. Piriform released CCleaner for Android in 2014. Nine years later, the app was released for iOS via the Apple App Store.

On 6 October 2025, with the release of CCleaner 7 for Windows, it received a major UI overhaul, featuring a more modern interface, a universal dark mode, and support for ARM64 architecture. Version 7 also removes the options to close the software or to disallow it from running on startup.

Piriform was acquired by Avast in July 2017. In December 2018, it was reported that users installing CCleaner would also have Avast Antivirus installed without their permission, with TechSpot claiming this arguably made CCleaner no better than the malware it was supposed to defend against. Piriform denied this.

In July 2020, Microsoft Windows Defender began flagging the free version of CCleaner as a "potentially unwanted application", stating that "while the bundled applications themselves are legitimate, bundling of software, especially products from other providers, can result in unexpected software activity that can negatively impact user experiences." Piriform rolled out an update days later and third-party software installation is now optional when installing the program.