An actual attempt to spam and reCAPTCHA

[toplisek]

I like to set reCAPTCHA Verification only show up if there is an actual attempt to spam.

Which settings will actually do this inside Google eCAPTCHA using Javascript?

[keyplyr]

You could use a JS or PHP to set a few conditions (example: spammy words) and if present, display the eCAPTCHA.

However getting it to function the way you're thinking might be a lot of work depending on where you want to use it... in a form, in a text field, static page with input field, dynamic page?

And it would be more scripting in a time when we're trying to reduce scripting for the Mobile-First Index [webmasterworld.com]