Another said: "Make up your mind, either you're a beef burger restaurant or vegan burger restaurant."
Grill'd had mixed reviews after going meat-free for a day. Photo / Instagram
However, others support the chain's move, saying the burgers are tasty and is a positive way to encourage the plant-based movement.
"This is a great idea, much better than vegans raiding farms, stealing animals and barricading businesses - it's a reminder to everyone that you can enjoy food without meat," one person wrote.
"I had one of the new vegan burgers there and oh god it was amazing. Even my meat eating family loved the new burgers. The line was out the door and the restaurant was packed," another said.
Adding to their already existing vegetarian range, three new meat-free burgers have been included on their menu moving forward.