Is Recaptcha Effective for Blocking Bots in Web Chat?

Honestly, any captcha can be bypassed by determined bots. The main point of using them is to make it harder for bots to send messages; if it's too easy to bypass, they won't bother. So you might want to consider how much hassle this solution is worth to you.

You could also look into alternatives like HCaptcha. I think their puzzles can be annoying though, so if you want a smoother experience, Turnstile may be the better route.

If you're looking for alternatives, you might want to check out Cloudflare's Turnstile. It has a silent mode that can help reduce friction for users while still filtering out some spam. Just keep in mind, though, that no captcha solution is foolproof, and some junk messages might still slip through.