Short answerTwo different jobs:
- DaisyDisk is a disk-space map. It scans your drive and shows what's using space; you spot the big stuff and drag it to the trash yourself. Fast, and a one-time purchase.
- Noah is a fix-it tool. You say “my disk is full” (or “my Mac is slow”) and it finds the cause and clears the right thing with your OK — and it handles problems that have nothing to do with disk. Diagnosis is free.
Want to hunt big files by eye? DaisyDisk. Want the cause found and fixed? Noah.
| Noah | DaisyDisk |
|---|
| What it's for | Finds and fixes the problem you describe | Shows what's using disk space |
|---|
| You or the tool decides | Noah finds the cause and proposes the fix | You read the map and delete by hand |
|---|
| Covers non-disk problems | Yes — slow, hot, Wi-Fi, crashes, more | No — disk space only |
|---|
| Changes to your Mac | Shown first, done only with your OK, logged | You delete files yourself |
|---|
| Pricing | Diagnosis free · $29 one-time or $79/yr | One-time purchase (see DaisyDisk) |
|---|
| Platform | Mac (Windows & Linux emerging) | Mac |
|---|
The real difference
DaisyDisk answers one question, well: what's using my disk? It draws a fast, clear map of your drive and lets you drag the big stuff out. But it's on you to know what's safe to delete — and it only sees disk space. If your Mac is slow for some other reason, a disk map won't tell you.
Noah starts from your symptom. Say the disk is full and it finds why — old snapshots, caches, forgotten large files — and clears the safe-to-remove parts with your OK. Say the Mac is slow and it checks whether disk is even the cause, or whether it's memory, a runaway app, or something else.
Deleting safely
With DaisyDisk you're the one deleting, so being sure a file is safe to remove is your call. Noah only proposes safe-to-remove space, shows you exactly what it'll clear, waits for your OK, and logs it.
Which to pick
DaisyDisk if you like a visual map and want to hunt large files by hand. Noah if you'd rather be told what's wrong and have the right thing cleared for you — and want it to cover the non-disk problems too.
Try Noah freeA Mac that just works.
Just tell Noah what's wrong:
My disk is full again.
Frequently asked questions
Is Noah a DaisyDisk alternative?
If your goal is to free up space, Noah does that — it finds what's safe to remove and clears it with your approval. DaisyDisk is more of a manual tool: it shows you a map and you delete by hand. Noah also covers problems that aren't about disk at all.
Does Noah show a disk map like DaisyDisk?
No. Noah's approach is different: instead of a map for you to read, it tells you in plain English where the space went and clears the safe parts with your OK. DaisyDisk is the better pick if you specifically want the visual map.
Can Noah find hidden space like local snapshots and caches?
Yes — those are the usual reasons a Mac is full when your own files don't add up. Noah finds them, shows you what it'll clear, and removes nothing without your approval.
One-time or subscription?
Both avoid subscriptions for the core job. DaisyDisk is a one-time purchase. Noah's diagnosis is free; applying a fix is a one-time $29, or $79 a year for Guardian.
DaisyDisk is a trademark of its owner; this page is an independent comparison and isn't affiliated with or endorsed by them. Product details change — check their site for current features and pricing.