I made an unlimited free captcha service.
I used altcha before, but it only focuses on Pow which was kind of hard to figure out bots.
So,I made this service. It tests Pow+11 more stuff on your browser and updates every 10 minuites to stop new bots, is light, and easy to use! Maybe you should consider using this?
There's a test for this: sh.krl.kr/test
Hope this is great for you!
Website: sh.krl.kr