Google Flights is already awesome for searching and tracking flight prices. However, they just updated the tool to make it even more useful: It will now tell you when to book to get the best deal. When you're looking at a specific flight, Flights will tell you when and if prices for that flight are likely to increase. A little notification screen will pop up and tell you how much more your ticket will be if you book later -- helpful if you're trying to scoop up the best deal.
Google Flights has always given "tips", which are basically just notifications telling you how to save money by flying a different day or airport. A new tip will also tell you if that route has experienced any price jumps in the past.
In short, Flights now offers a little more insight on the best time to book. Of course, you can still track these flight prices, too.
Google also made some updates to their hotel search. When you browse lodging, Google will now show you what historical pricing looks, depending on the date and the hotel, so you can see if the rate is normal or if it will likely be discounted in the future. There's also a new "Deals" filter where you can search for cities with hotel discounts. Google can also so notify you when there are savings for a certain hotel's loyalty members.
You'll see the changes next time you search for hotels via Google, and you can check out the changes to Flights at the link below.