Baggage Info | Carry-Ons and Checked Baggage | JetBlue

What the official page says

Carry-on bags must not exceed 22" L (55.88 cm) x 14" W (35.56 cm) x 9" H (22.86 cm), including wheels and handles. Personal items must not exceed 17" L (43.2 cm) x 13" W (33 cm) x 8" H (20.32 cm). No carry-on weight limit is published.