Options
Captcha alternatives
Teams look for a captcha alternative when picture tasks frustrate visitors or a third-party script is hard to justify.
Choices
Three patterns you will meet.
Proof of work
The browser spends a little computing time.
CDPCaptcha is this pattern, with no cookies and a self-hosted option.
Managed signals
A large operator scores the browser and often shows nothing.
You depend on that operator for every page view.
Your own server
The verify call stays on infrastructure you run.
CDPCaptcha can be installed that way, or used as the hosted service in Germany.
The captcha comparison names the well known products.
The features page lists what this one includes.
Start with one form
Replace a single form first and keep the server side check in your application.