Legit is a shortened version of legitimate which means something is conforming.
“Seems Legit” is used as a sarcastic reaction in situations, where something deceptive or questionable is happening and the user can easily predict this happening.
It can be said that the term was first introduced when the song called “Too Legit to Quit” was released by MC Hammer in 1991, however it was only used in its context now, 15 years later on a computer hardware forum as a sarcastic reply. After this, it took a few years for the reaction to be recognised.
3 years after its appearance on the computer hardware forum, the term was added to the website Urban Dictionary where its context and meaning was first explained, then went on the conquer the internet.
Many examples of the use of it can be found on the websites Reddit, Very Demotivational, Tumblr and its own hashtag, #seemslegit.
Tons of content was created as sarcastic images and screenshots At this point, the term has already found its way to everyday speak, even outside the internet.