I think it is too risky if I made a bitcoin address on your website, because you can see my private key,please answer,whether you can guarantee my private key, if I would try to make bitcoin address here?
bitaddress.org isn't (99.99% sure) owned by the person selling vanity addresses. The site has been on for a while and most people trust it. It's open source too, so people can inspect the javascript. Worried that the person has a different version on the site? Download the code from github and run it locally.
I guess the admin will know the private key is created, it does not! , whether this website provides a free for some characters?, and Good luck with what you're doing right now.
bitaddress.org doesn't offer vanity generating services. You can generate vanity key pairs though.