Why is FlightStats' information for a particular flight occasionally different than the information on other publicly accessible sites?

Jeff Moyer

You will inevitably see differences when comparing the information from multiple sources. This happens because:

There is no central source of flight data, which means different sites may be getting their information from different sources.
When data is made available it will not reach all the different sites at the same time.
You may not be making an apples to apples comparison. Many sites only use runway times, FlightStats uses both gate times and runway times.
Sometimes site A will not have access to the same information as site B for a particular flight.