Starting Wednesday, customers will get a code on their receipts that they can share on social media.
The first person to click on the code will get to get an offer for a free burger.
The promotion is meant to draw younger customers to TGI Fridays, CEO Nick Shepherd told Bloomberg.
"You promote because you're chasing guests and you want them to try you," Shepherd said. "We wanted to connect with younger guests to come and try Friday's and see that it's something different."
TGI Fridays' US sales fell 1.5% last year to about $1.6 billion, according to Technomic data cited by Bloomberg.
The chain ran a popular promotion last summer that offered endless appetizers for just $10.