Continuity mistake: In the scene at the college where Callaghan asks to look at Hiro's Megabot, Callaghan's shirt is blue, but when he holds out his arm to take Megabot, his shirt sleeve is red. Later on he is wearing a red shirt at the SFTT. (00:13:30)
Continuity mistake: When Honey meets Hiro, she has earbuds in her ears playing music. She starts talking to Hiro, pulls them out of her ears, and they dangle out of her shirt. The dangling earbuds disappear in the close up shot of her and Hiro.
Continuity mistake: When Hiro and Baymax are in the warehouse the single microbot is let go by Hiro before they are attacked, linking with the others. A few minutes later, the microbot is seen back in the Petri dish again before they are attacked.
Suggested correction: Microbot was always in Hiro's pocket and never joined others.
Continuity mistake: At the end, Baymax rocket-glove changes model. When Baymax puts his Rocket-glove at the thruster on the ship it has the original model seen earlier in the movie, however, when the ship exits the space through the portal and the glow shuts-down it has another model. (01:27:00 - 01:29:00)