Key Takeaways Frontier on Tuesday announced free seat selection, flight changes and checked bags for a limited time. The budget airline's moves follow steps in the other direction by Southwest Airlines.

"Breaking up with your old airline? We’re here for you!" said Frontier Airlines. The Denver-based airline said a new free bag policy could become permanent.

Frontier Airlines is stepping up its game. The airline announced Tuesday via press release that it will offer customers a free checked bag on select flights this summer.