Originally Posted by
StraightShooter
Is there a website that can build connecting flights between carriers to help plan a commute?
For example, from DEN to IAH on Southwest, then IAH to MIA on United.
No specific website that I know does this, but you can backdoor Passrider. Go to:
Passrider.com/mobile (no ads on mobile site

)
Type in city codes and date & hit show schedules..
In results page go to the address/url bar and find where it says "interline=N" and change it to read "interline=Y" hit enter...
Voila, you have interline itineraries.

happy commuting.