On GrubHub, there is a separate menu which mirrors the regular menu. So it will say, "VG Burger (GF)"... Which makes me super confident that they know which items need to be prepared GF. Also, there is a really inclusive online allergen list.
Food is amazing! I would not know it's all vegan. The nachos are great, and so is the VG burger.
— Separate gluten-free menu