Lets say you have a comment section on your site where any user can write stuff.
More often than not a hidden field which should not be filled (the honeypot method) and a spam filter gets the job done no problem.
For registrations it can be more problematic because the spam filter does not work that well.
I have yet to find a good alternative to commercial captchas as well but rolling your own solution is possible.
And probably even the best idea because if every site has its own weird system it would make the life of bots quite hard.
In the end a dedicated attacker can always hire people to fill the captchas and circumvent any system for an astonishingly low amount of money.
Lets say you have a comment section on your site where any user can write stuff.
More often than not a hidden field which should not be filled (the honeypot method) and a spam filter gets the job done no problem.
For registrations it can be more problematic because the spam filter does not work that well.
I have yet to find a good alternative to commercial captchas as well but rolling your own solution is possible.
And probably even the best idea because if every site has its own weird system it would make the life of bots quite hard.
In the end a dedicated attacker can always hire people to fill the captchas and circumvent any system for an astonishingly low amount of money.