How far in advance should I book flights for the best prices?

There is no single magic day, but there is a reliable window. For domestic routes, roughly six to eight weeks before departure tends to sit in the sweet spot between early inventory and last-minute panic pricing. For international routes, two to four months out is the usual band. Around major holidays, school breaks or big local events, move earlier again — four to six months is not excessive.

What makes a bigger difference than the exact day you book

• Set alerts rather than refreshing. Google Flights, Skyscanner and Hopper will all watch a route for you and tell you when it moves.
• Shift your dates. Leaving a day earlier or later — especially flying Tuesday or Wednesday instead of Friday or Sunday — is often worth more than any booking trick.
• Compare nearby airports. A second airport an hour away can change the fare noticeably, but count the transfer cost and time before you celebrate.
• Check the airline's own site before paying. Once you have found a fare on a comparison site, the direct booking is sometimes the same price and much easier to change later.

You will see advice about searching in incognito mode to dodge cookie-based pricing. It costs you nothing to do, and it removes one variable, but do not expect it to be the thing that saves you money — flexibility and lead time do the heavy lifting.

One honest caveat

Waiting for a fare to drop is a gamble. If a price is already good for the route and season, and the ticket is refundable or changeable within 24 hours, taking it is usually the better decision than chasing a hypothetical cheaper fare.