Are keyloggers legal?

[TereseGT]

Is it safe to use them for my personal needs?

Illegal if used for criminal activity.

It depends on exactly what you intend to use it for.

It is legal if you put it on a computer owned and used by you.

I agree with other responses, keyloggers are definetely illegal if you use them for stealing any personal information from other people, for example it's a popular practice for various types of scam.
This type of software can work in a hidden mode and it records all keystrokes made on a certain computer, as also many other information like web searching, e-mail, social networks activity, text documents and so on. Because of that keyloggers are very convinient for monitoring anyone's gadgets activity and installing them on computers is often used in case of office workers too. But anyway, according to the law all employees must know about this software before starting to use their computers. Without this it'll be illegal too blog.flexispy.com/ru/keyloggers-in-the-workplace/.
But if you use keyloggers just for your personal needs, it's ok and legal, as also in case of your underage children, keylogger software www.refog.com/ is a popular element of general parental control tools too.

As others have said, it depends what you’re using it for.