Spirit vs Frontier Baggage Fees

Both ultra-low-cost carriers charge high bag fees. Frontier is slightly cheaper. The golden rule: always add bags at booking — airport fees are 30–50% higher.

• Personal item: Free on both (18×14×8 in)
• Carry-on at booking: Frontier $29–75 · Spirit $39–89
• Carry-on at airport: Both $65–99 — avoid this
• First checked bag at booking: Frontier $29–79 · Spirit $39–89

See also: Frontier carry-on size · American vs Southwest baggage fees · Carry-on vs checked bag