In texting, "tbh" is an informal abbreviation for "to be honest". It is often used to express an honest opinion, make a comment, or admit something. For example, someone might say "tbh, I dont like the Star Wars movies" or "tbh, that shirt is not your color". On Instagram, "tbh" can also mean that someone will share their opinion of you if you like their post. If you come across the abbreviation "tbh" in a message, its likely that the sender is trying to express their honest opinion about something.