Is Steam Achievement Manager Safe?

Yes, our testing and scans revealed that it is a safe app without any malware or viruses.

Is Steam Achievement Manager bannable?

There is no proof that anyone has ever been banned from by using it. It does go against Steam's Terms of Service (ToS) and there are rumors that you can get banned but it has never been proved. We advise you to proceed with caution and at your own risk as this is still considered cheating/exploiting because you're unlocking stuff that you've not earned via a third-party software.