Skip to content
OpenDisk
FeaturesSpeedCompareFAQChangelog
GitHubDownload
FeaturesSpeedCompareFAQChangelog
GitHubDownload

Guides

Get your disk space back

Plain answers to the questions Mac owners ask most about storage.

  • What is System Data on a Mac, and how do you shrink it?

    System Data is the catch-all in macOS storage settings. Here’s what’s usually inside it, what’s safe to remove, and how to find the big parts.

    Read guide→
  • What is purgeable space on a Mac?

    Purgeable space is storage macOS counts as free because it can clear it on its own. Here’s what it is, why it sometimes won’t clear, and what to do.

    Read guide→
  • How to free up space for a macOS update

    A macOS update needs room for the download and the installation. Here’s how to see how much you need and get it back quickly.

    Read guide→
  • How to find large files on a Mac

    Four ways to find what’s taking up space on your Mac, from built-in macOS tools to Terminal and a visual disk map.

    Read guide→
OpenDisk

A fast, free, open-source disk space analyser for macOS.

v1.5

Product

  • Download
  • Mac App Store
  • Homebrew
  • Features
  • Speed
  • OpenDisk vs DaisyDisk
  • FAQ
  • Guides

Updates

  • Changelog
  • Release notes (v1.5)
  • All releases
  • Sparkle appcast

Open Source

  • GitHub repository
  • MIT License
  • Contributing
  • Build from source
  • How it’s fast

Support

  • Contact support
  • Report a bug
  • Request a feature
  • Full Disk Access help
  • Press kit
  • Privacy policy

© 2026 OpenDisk contributors · Released under the MIT License · Privacy

Apple, Mac, and macOS are trademarks of Apple Inc. DaisyDisk is a trademark of Software Ambience Corp., referenced for comparison only. OpenDisk is an independent open-source project, not affiliated with or endorsed by either company.