Experience
Invisible captcha
Invisible usually means the visitor never sees a puzzle, not that the page loads a hidden tracker.
CDPCaptcha
Work in the background, status still available.
Starts on its own
The widget can begin the proof of work when the page loads, so many people never press anything.
Still a button
One button stays available for keyboard users.
Hiding every control would block people who need it.
Not a tracker
No cookie and no third-party call are added to make the check quiet.
The work happens in a Web Worker.
Watch it on a test page
Use the playground or a sitekey on a page you control.