There's just one problem -- because a ton of the data is cached, or precomputed, or however it's done, a substantial and frustrating amount of the data is simply wrong. As in, an unbookable flight. I spend probably an unreasonable amount of time searching for flights, and anecdotally I'd say about 5-10% of the results I get (not even for complex itineraries) either have a completely incorrect price, or are wholly unbookable on any website. Calling the airline doesn't count, because if their website doesn't have it, 99% chance neither will the call center.

For example, one from a few hours ago: https://www.google.com/flights/?f=0#f=0&flt=/m/01lfy./m/02_2...

The QPX search engine is actually the same behind Google flights and all the airlines and what Orbitz used to use. The limitation pre google/flights was the on-demand querying only.

Now the contiguous querying, obviously, gives you a load of useful historical data. After running it for a couple of years now they seem to feel confident that they can predict prices changes with enough accuracy that the payouts for misses will be an acceptable price for the publicity, or increased use of their other travel products.

(disclaimer: ex-ITA/Xoogler, opinions my own)

The result is that sometimes the information they display can be out of sync with airlines. You should notice this issue more on rarer flight routes.

Such nonsense.

Pretty much all airlines don't own/run the source of truth for their flights and haven't for decades. They outsource that to GDS[1] such as Sabre and Amadeus. Their backends are not fragile.

You just have to pay for every query thus the caching.

[1] https://en.wikipedia.org/wiki/Global_distribution_system

My solution so far is to search for broad prices for my approximate dates on Google, and when I see something promising open a new tab and go straight to the airline's site where I search for an actual offer for a specific flight.

I've found Google Flights super useful this way, though I guess they make less money on me than they could.

Perhaps, but I was never impressed with Orbitz during its heyday. I remember watching a Google tech talk* about how hard a problem it is to give the searcher a viable set of options to chose from. However, in my experience, the viable set of options always seemed to include a 23 hr layover with with multiple connections that was $200 cheaper than the nonstop option, and various single connection 1hr layover options about $150 cheaper than nonstop. At the time, both Expedia and Travelocity offered a more reasonable set of options.

* can't seem to find it right now. Will post if able to locate later.

Fare Construction (can be useful to travel agents) CPH SK X/MAN VS NYC 500.77HLHF06MN NUC 500.77 END ROE 6.637696 XT 161ZO 167UB 39YC 47XY 27XA 124US 646YQ

I wish that Google Flights would offer a way to get this info in the UI; it's not common but not greatly unusual to be in this position (where Flights can find the fare but the UIs available to consumers can't book it).

Funny story: just last week I was booking a complicated multi-city trip with 5 legs, multiple countries, etc. I tried several times via united.com, and it wasn't showing me any flights available in one of the legs (which I knew they had a codeshare agreement).

I went back to Google Flights, chose all my flights, selected "Book with United", and was able to finish the reservation on united.com (!), with all the flights properly populated, including codeshares.

It's remarkable that the integration between Google Flights and the airlines is better than even the airlines' websites themselves.

But validating and pricing any single itinerary is a trivially easy problem ("P"), so United can handle that no problem. It can't come up with the itinerary, but given a particular one, it will sell it to you.

So no, there's no special magic here.

Google Flights is destined to be on chopping block sooner or later. It has not much influence on core business and is not going to be wildly profitable. The problem is that by the time Google kills it, Kayak and other competitors would be forced in to unrecoverable comma or just outright killed off as well.

Really? I've yet to see a flight be cheaper or close to what the likes of Kayak and Skyscanner have provided.

What sets it apart is the UI and fast search. But I guess with fast searching (caching) comes inaccurate results. It’s a thin line.

Iirc I stumbled upon one of the flight tracking services by pure chance.

Having said that, I feel like Skyscanner at the very least has their own systems in place. There have been times where I've chosen a ticket, have gone through to the website that sells the ticket at the price, and just before it goes through, Skyscanner validates that the price still exists, and then bails saying the price has increased or decreased. Usually it's not by a lot, but it has happened.

Multiple times flying from random places in Africa to Australia return, and Australia to Canada, GFlights was at least $1k more than the cheapest on kayak or orbitz.

Maybe GFlights just doesn't show overly cheap options..?

Don't be surprised that many other travel sites cannot compete. After all, most of the sites are owned by either Expedia or Priceline. They are not startups. Also, they focus more on hotels since that's where the money is.

Is there?

Expedia Group owns: Expedia, Ebookers, Orbitz, and Travelocity.

Booking Holdings owns: Priceline, Agoda, Kayak, Momondo, and Cheapflights.

Ctrip Group owns: Trip.com, and SkyScanner.

Earlier this week Google had fewer flights than Expedia.