Inventory what matters
WhatSize can show detailed tables but has no migration path — save or screenshot your key measurements, then verify them with a NullDisk scan before queuing anything for removal.
What you can take with you
WhatSize
WhatSize can show detailed tables but has no migration path — save or screenshot your key measurements, then verify them with a NullDisk scan before queuing anything for removal.
Step by step
Run a fresh NullDisk scan
Open NullDisk, pick the same volume or folder, and let it measure everything — allocated size, hard links included. What you see now is ground truth.
Rebuild your cleanup queue
Drag each flagged item into the Ready-to-Remove collector. Review sizes, previews, and paths at leisure — nothing is deleted yet.
Trash once, verify twice
Move the collector to the Trash in one step, then rescan to confirm the reclaimed space. Uninstall the old tool only after the numbers check out.
Frequently asked questions
Can I export reports from WhatSize?
WhatSize can show detailed tables but has no migration path — save or screenshot your key measurements, then verify them with a NullDisk scan before queuing anything for removal.
Will I lose anything by switching?
No — scans are reproducible. A fresh NullDisk scan of the same volume shows the same files with allocated-size accuracy, usually within minutes.
Is NullDisk hard to learn after WhatSize?
Most switchers are productive in minutes: the radial map reads instantly, and the collector mirrors the 'gather then delete' habit you already have.
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