Your program sends the service the page address and the captcha's key. The service answers with a token, and your program submits that token with the form as if a person had solved the puzzle.
Many sites tie the token to the IP address that requested it. If the service solves from its own address and you submit from yours, the token is rejected. The fix is to give the service your proxy, with the same sticky session you use yourself, so both steps come from one address.
Questions about captcha solver
Do I have to give the solver my proxy?
Only for captchas that are tied to the IP address. For those, send the solver the same proxy and the same sticky username you use, so the token is valid when you submit it.
Why was my solved token rejected?
Most often it was solved from one address and submitted from another, or it had expired. Tokens are short-lived, usually good for a couple of minutes.
Related terms
- Captcha
- A captcha is a test a website shows to check that a visitor is a person, such as picking images or ticking a box, before letting them continue.
- Sticky session
- A sticky session keeps the same proxy IP address for a set time, so several requests in a row look like they come from one visitor.
- Bot detection
- Bot detection is the set of checks a website runs to tell people from programs: the IP address, the browser fingerprint and the behaviour.