How does re-captcha work?

Question

In several sites in internet, bots are avoided using re-captcha by google or some else company.

I want to know, how does server knows that user is not a bot?
Bcoz, re-captcha is itself a bot. It means, it sends a unique data to server that tells a server that, user is not a bot.

But, same idea can bypass recaptcha, isn't it?
How it actually tells server about user is not bot??

Answer 1

Checker 8763

I know these all.

I just want to know, how Recaptcha tells server that user is not a bot.
I mean, how it sends/speaks/says that data to server? 😕

Answer 2

Checker 8763
Thanks, I'll read the whole documentation of Recaptcha.

https://developers.google.com/recaptcha/

Answer 3

From what I know it collects all sorts of data it can get from the user.
Something like cookie data, behaviour on the website, timings and clicks. Or if he can track the users history to other sites.

Based on all that data the re-capcha from google can tell if it is a human or a Bot.

I am not 100% sure about if this is correct, ply correct me uf I am wrong!

Answer 4

To use a Capcha it has to be implemented in the html form, the capcha will return the user-id which can then be checked via the api if its token is valid or not.(Link below)

Or if you work with a self made capcha the php script knows the original string an just checks if it matches with the one entered.

Maybe that will help:

https://developers.google.com/recaptcha/docs/verify

Answer 5

I think google not traffic from ur device...then guess its rebot or human

Answer 6

Recaptcha was method used by Google to train his AI.