In 2011, Google purchased ITA, the company that powers airline comparison shopping for sites like Travelocity, Priceline, and Expedia. Their intent was to incorporate flight searches into Google, and that's exactly what they did. They've also eliminated one of my biggest beefs with flight pricing: the incredibly long delay when you hit search. It's still far from perfect. You can't yet double up and find your hotel and rental car at the same time, for example, but I still use Google to double check that my search on a different engine is providing me with all the results and the best prices.
Getting to Google Flights
You can start by just typing a search into Google, like "flights from MCI to NYC in October." The context will be enough to pull up the flights search in the left options menu in your Google search. If that fails, you can always just go directly to "www.google.com/flights."
Beginning Your Search
Google Flights starts with a map of the US, because that's currently the only place you can comparison shop for tickets. International tickets are off the menu for now.
First you'll need to enter a departure point and destination. If you're logged into Google, your departure point may already be set based either on your default Google Maps location or your laptop's current location. It may also have been set by by your earlier search, which is one handy reason to start with the Google search. As soon as you've got those points set, you'll see your proposed flight points on the map. It certainly makes it easy to verify that you did pick the right Springfield.
Next, you'll enter a date of departure and return in the box below the map. As soon as you've done that, you'll either see flights or a message that flights between those two points are not supported.
Usually you've got a price in mind when you search for tickets, or maybe you have a flight duration, arrival time, or specific rewards network in mind. Google can handle a lot of these requests.
First you'll notice right below the Depart and Return boxes, there are Depart and Duration boxes. You can use these individually to filter results instantly. You can also use the funky looking graphic box to the right of the Depart and Duration boxes to adjust both items at once. Once you click on that, you'll see a graphic slider with dots. You can see all the results that fit within your parameters as dots, and you can adjust the sliders until you know you've found a good balance between convenience and availability.
What if you don't care how long the flight is as long as it's nonstop? Google can handle that. Rather than using the graphic slider, check out the options on the left. You can limit results to nonstop flights, one stop or less, or two stops or less.
While we're at it, you can restrict your search to specific airlines, so you can stick with the company you know gives you mileage upgrades or free checked luggage. (It's still up to you to track which company that is.) You can also specify where you want to connect. That might be useful if you know you're going to wait for a three hour connection in an airport with free Wi-Fi.
Finally, you can also specify an outbound and inbound time. Click on the link marked specific time and use the slider to specify your travel window. I use this when I want to return from a conference without spending an extra night at the hotel.
Some airlines won't share their prices with ITA. Mainly it's Southwest. You have to book directly. However, Google will still show you when they're flying that day, so you can check the price with their website and then compare it to the prices you've seen with the other airlines.
Booking Your Flight
Once you've chosen your flight, you can click on the price, and it will turn into a button that says Book. Clicking the button takes you directly to the airline's website where you can book the flight. This even works when the flight is actually on two different airlines. You still only need to book the flight on one airline, and it will know exactly the details you need. If you're booking on Southwest or another "unknown price" airline, you won't get a Book button. You'll need to go to the airline's website and book it from there. However, if you want to book a flight and hotel, it might be worth your while to check to see if Travelocity or some other company doesn't have a better combined vacation package deal.