DiskBuddy shows where the space went. Disk Forecast shows when it runs out.
DiskBuddy launched in September 2026 and has shipped fast since, adding a finder for local AI models in its 3.0 release. It's a strong paid app. Disk Forecast is the free one that warns you weeks before your disk fills.
The short version
Pick DiskBuddy if you want the biggest toolbox in one paid app, including duplicates, compression, and a Windows license on the same key. Pick Disk Forecast if you want a countdown to a full disk, System Data explained with Apple's own fixes, and the source on GitHub, for free.
What DiskBuddy does well
DiskBuddy launched on September 5, 2026, changed hands about a month later, and shipped version 2.0 on September 23 and 3.0 on October 4. It's ambitious. There's an overview, a space map, a tiered cleanup list, duplicates, apps, a monitor, snapshots, activity, compression, a menu bar item, and a finder for local LLM models.
It sends deletions to the Trash, it scans about 3 million files in roughly 20 seconds by its own numbers, and one license covers a Mac and a Windows PC.
Where it stops
It's paid, and the price has moved. It launched at $19 with a counter of copies left, and the site now lists $49.
It answers “what's using my space?” We couldn't find anything in its materials that answers “when will I run out?”, which is the question Disk Forecast is built around.
System Data gets a snapshots view. Disk Forecast breaks System Data into every part it can measure, explains each in plain English, and fixes it with Apple's own tools.
Disk Forecast vs DiskBuddy
DiskBuddy facts come from its launch and release posts, September to October 2026.
| Disk Forecast | DiskBuddy | |
|---|---|---|
| Price | Free | $19 at launch, now $49 |
| Tells you when the disk will be full | Yes, in the menu bar | — |
| System Data broken down | Every part, in plain English, with Apple's fixes | Snapshots view |
| Cleanup sorted by risk | Yes | Yes |
| Deletes go to the Trash | Yes | Yes |
| Finds local AI models | Ollama, LM Studio, Hugging Face | Yes |
| Duplicate finder | No | Yes |
| Windows version | No | Yes, same license |
| Source available | Yes, on GitHub | — |
| Telemetry | None | — |
“—” means we couldn't confirm it from the vendor's own materials as of October 2026.
What DiskBuddy does better
Breadth. Duplicates, an apps view, compression, activity history, and a Windows version on the same license. If you want one paid app that does all of it, DiskBuddy is a good one.
What Disk Forecast does better
It tells you ahead of time. Free space and a countdown sit in the menu bar, System Data comes with a plain-English explanation for every part, and the whole thing is free with the source on GitHub.
Trying it takes a minute
- Install Disk Forecast.
brew install --cask coreyhaines31/tap/diskforecast, or download the app from GitHub and drag it to Applications. - Let it learn for 3 days. Free space shows in the menu bar right away. The forecast appears after 3 days of history.
- Open System Data…. See what macOS has been filing under the gray bar, and fix the parts worth fixing.
- Keep DiskBuddy if you use its extras. They don't conflict. Plenty of people will want both.
Questions
How much does DiskBuddy cost?
DiskBuddy launched at $19 with a limited run of launch copies, and its site has since listed it at $49. Check DiskBuddy's site for the current price.
Does DiskBuddy move files to the Trash?
Yes. DiskBuddy sends deletions to the Trash, and so does Disk Forecast.
Does DiskBuddy tell you when your disk will be full?
We couldn't find a forecast in DiskBuddy's own materials as of October 2026. In Disk Forecast it's the headline feature: a countdown in the menu bar, built from your own daily history.
Is Disk Forecast free?
Yes, at home or at work, with no account. The source is on GitHub and the app collects no telemetry.
Other Mac storage apps, compared
Get the forecast, free.
Free. No account, no subscription.
macOS 14 or later · Apple Silicon and Intelbrew install --cask coreyhaines31/tap/diskforecast