Flight Check

Best Airline: PHL to DEN

Philadelphia to Denver — airline reliability comparison

United Airlines is the most reliable airline on the PHL to DEN route with a 86% on-time rate, compared to Frontier Airlines at 69%. Based on 3,481 flights tracked.

This route involves weather-prone airports and high-congestion airports, which can affect reliability regardless of airline.

Source: Bureau of Transportation Statistics. Updated October 2026.

On-Time Rate by Airline

United Airlines86%
Southwest Airlines76%
American Airlines74%
Frontier Airlines69%

PHL to DEN Airline Comparison

AirlineOn-Time %Cancel %Avg DelayFlights
United AirlinesUABest86%0.9%94m3,481
Southwest AirlinesWN76%0.6%57m2,638
American AirlinesAA74%1.7%72m2,997
Frontier AirlinesF9Worst69%2.3%97m1,341

Route Overview

78%
Overall On-Time
78m
Avg Delay
1.3%
Cancel Rate
10,466
Total Flights
PHL to DEN Route DetailsReturn: DEN to PHL
PHL AirportDEN Airport

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Data last updated October 2026. Source: Bureau of Transportation Statistics.