What does it mean if he texts I love you?

It depends who this guy is to you...

I have a guy best friend, he's like a brother to me and he always tells me he loves me. In a family way, does he mean it like this?

However if you think this guy may have feelings for you then maybe he said it at the end of the text because he wants to tell you but hes shy, and he has just quickly typed it and press send...

If you feel the same way, say it back?

If not ask him politely, what has made him feel this way, is it new to him and if you like him, ask him out!

He sounds sweet if you ask me ;-)