Compare
Captcha comparison
These products all try to slow automated form abuse, and they ask the visitor for different things.
This page does not rank them.
Approaches
What each check is known for.
Proof of work
The browser does a short calculation.
No picture puzzle, no cookie, and you can host it yourself.
Made and hosted in the EU, in Germany.
This product
Google service
It is operated by Google and has used picture tasks as well as a risk score.
The script is a third-party request on the page.
External service
Image tasks
People are asked to label images.
The service is operated by a separate company, not on your own server.
Picture labels
Friendly Captcha and Turnstile
Friendly Captcha is another proof of work product.
Turnstile, from Cloudflare, checks the browser without a picture puzzle.
Different operators
Migration notes for teams that already have a widget are in the migration guide.
Try the proof of work on a form
A sitekey lets you compare the visitor experience on a page you control.