OpenDisk is a free, open-source disk space analyzer for Mac. It scans your drive and shows the results as an interactive sunburst chart, so you can see exactly what is taking up space and dig into any folder with a click. It works as a fast, free alternative to paid tools like DaisyDisk.

Key Features

• Interactive Sunburst Chart: Each ring in the chart represents one level deeper into your folders. Hover a slice to see its size, or click to zoom in.
• Live Scanning: Results stream in as the scan runs, so the chart and folder list fill in while you watch, instead of waiting for the whole scan to finish.
• Fast Rescans: OpenDisk reuses data from a previous scan, making a repeat scan up to 28 times faster than the first one.
• Accurate Space Reporting: It understands APFS volume groups, firmlinks, and purgeable space, so the totals match what your Mac reports as used.
• Instant Search: Search across your entire scanned drive, with results appearing as you type, even on drives with millions of files.
• Collector: Drag files and folders into the Collector from anywhere in the app, check how much space they will free up, then delete them all at once.
• Free and Open Source: OpenDisk is released under the MIT license, so its code is public and it costs nothing to use.

Frequently Asked Questions (FAQ)

Is OpenDisk free?

Yes. OpenDisk is completely free and open source under the MIT license.

What macOS version does OpenDisk need?

OpenDisk needs macOS 26 (Tahoe) or later, and it works on both Apple Silicon and Intel Macs.

How do I install OpenDisk?

Download it from the GitHub releases page, unzip it, and launch it. OpenDisk will offer to move itself into your Applications folder and keeps itself updated automatically after that.

Why does OpenDisk ask for Full Disk Access?

Without Full Disk Access, macOS hides parts of the filesystem from OpenDisk, which makes its totals come up short. Granting access lets it scan everything and report accurate numbers.

How is OpenDisk different from DaisyDisk?

Both show a similar sunburst chart, but OpenDisk is free and open source, while DaisyDisk is paid and proprietary. In testing, OpenDisk scanned a 1 TB drive in 17 seconds, compared to 37 seconds for DaisyDisk.

Does OpenDisk work with external drives?

Yes. External drives appear automatically in OpenDisk as soon as you connect them.