Disk Drill

Scans a volume, shows you thumbnails of what it can get back, and only then asks for money.

What it does

Point it at a disk and it runs a quick scan for deleted entries and a deep scan that carves by signature, then lists results with previews. It also does the surrounding jobs: a byte-to-byte image of a failing drive before you touch it, S.M.A.R.T. monitoring, and a Recovery Vault that records metadata for deletions that have not happened yet.

The free build on macOS scans and previews without limit, and recovers only files protected in advance by Recovery Vault or Guaranteed Recovery. Everything else needs the paid tier.

Notes

The preview is the useful part of the free build: it tells you whether paying would achieve anything before you pay.
Recover to a different disk than the one being scanned.
One licence covers macOS and Windows, sold annually or as a perpetual key.

Same physics as everywhere else in this category: TRIM plus full-disk encryption means deleted files on an internal Apple SSD are usually unrecoverable by any tool. External spinning disks and cards are where these scans earn their keep.

Alternative to

Alternative	Type	Trade-off
TestDisk & PhotoRec	Open source	Free and at least as capable at carving, with a terminal interface
Data Rescue	Subscription	The older Mac incumbent; subscription only
Recuva	Freemium	The equivalent free-tier recommendation on Windows
EaseUS Data Recovery Wizard	Freemium	Comparable, heavier marketing, similar results
Stellar Data Recovery	Freemium	Adds video repair; slower deep scans