Hotels.com vs Booking.com.
Which is actually cheaper?

Why the two prices are so often identical

Hotels.com and Booking.com are both large online travel agencies, and both sign rate-parity agreements with the hotels they list. In practice that pushes the public nightly rate toward a match across channels, so the number you see on Hotels.com is often close to the one on Booking.com. Across our 14 snapshots of September 25 to October 1, 2026, 4,141 hotels were listed on both. Where both prices were on the same tax footing (3,348 hotels), their lowest prices were within $2 a night of each other at 58% of them; Hotels.com was more than 2% cheaper at 1,030 (31%) and Booking.com at 317 (9%).

So, on the same footing, neither site was always cheaper for the same room, but when their prices differed, Hotels.com was the cheaper one about 3.2 times as often as Booking.com (1,030 hotels to 317). When Hotels.com was the cheaper one, it was typically 10% below Booking.com. The differences that actually move money live in three places most people never check: the all-in total after taxes and mandatory fees, the loyalty programs, and the member or mobile-only rates each site can offer once you sign in.

Before tax or after

At the 2,812 hotels listing both where taxes and fees added 10% or more to the going rate (the price most sites agreed on), Hotels.com's price sat nearer the before-tax going rate at 167 of them and Booking.com's at 215. Where one of the two prices looked before tax and the other after (350 hotels), the before-tax one looked lower at every one. Part or all of such a gap can be tax that is added at checkout, so those hotels are left out of the counts above, and so are the 443 hotels where taxes added between 2% and 10%, where neither price's basis could be read. Leaving out the hotels whose going rates showed under 2% tax, 2,462 hotels remain, where taxes added 10% or more and each price's basis could be read: Hotels.com was more than 2% cheaper at 756 of them and Booking.com at 171.

How we measured: in each snapshot we recorded every booking site's price that Google Hotels showed a US searcher, in US dollars, and for each hotel took each site's lowest price, all-in with taxes and fees where the site reported them, otherwise its listed rate. Our data keeps one price per listing without saying whether it includes tax, so we infer it: where the hotel's after-tax going rate was 10% or more above its before-tax going rate, a price nearer the after-tax one counts as after tax and a price nearer the before-tax one as before tax; where the after-tax going rate was under 2% above the before-tax one (often because no site reported taxes separately), any two prices count as the same footing; hotels in between are left out. Within $2 means the two differed by $2 a night or less; more than 2% cheaper means one was below 98% of the other. The two can overlap on cheaper rooms (a $1.50 gap on a $60 room is both), which happened at 32 of these 3,348 hotels. A typical gap is the median, rounded down. A price we saw is one moment, not a completed booking. Method and the CSVs: our hotel price study.

Corrected October 2, 2026: an earlier version of this page compared the two prices at all 4,141 hotels listing both, including those where one price looked before tax and the other after, and said their lowest prices were within $2 a night of each other at 52% of them and Hotels.com was cheaper about twice as often when they differed (1,352 hotels to 599).

The differences that actually move money

• Loyalty: One Key vs Genius. Hotels.com now runs on One Key — the old "ten nights, one free" stamp card was retired and folded into OneKeyCash you earn after the stay across Hotels.com, Expedia, and Vrbo. Booking.com's Genius discounts you at checkout, typically 10–20% plus perks at participating hotels. One rewards later, one lowers the price now: compare the actual credit or discount against each site's all-in price.
• The all-in total. Taxes and mandatory resort fees can appear at different steps of checkout on each site. A lower headline rate can quietly carry a higher final total, so always read the price after fees on both.
• Member and mobile-only rates. Signing in — or booking on the app — sometimes unlocks a lower price on either site than the one you see logged out. It's worth a quick check before you decide.
• Property list. Booking.com leans widest on independents and European stays; Hotels.com's strength is the Expedia Group inventory and packaging. If your hotel only shows on one, that settles it.

And when a third site shows a much lower price than either Hotels.com or Booking.com, slow down: the lowest-priced listing is often an unverifiable wholesaler rate, and it may not be the same room or terms. That's exactly the kind of gap worth confirming before you switch.

Doing this comparison automatically

The tedious part is step 1 — opening Hotels.com plus Booking.com plus a few other tabs, scrolling each to checkout to surface the fees, and doing the all-in math. That friction is why most people just book the first rate they see.

Underbook is a free browser extension that runs that comparison while you shop. When you're viewing a hotel, it checks other booking sites for the same hotel and dates and shows the prices side by side: all-in, with taxes and fees, when the booking sites report them (at about 7 in 10 hotels in our price data), otherwise the listed rate, labeled as such, so where the sites report fees, a cheaper-looking rate can't hide one. When the cheaper listing doesn't name the same room, it says so plainly instead of inventing a discount. You always book wherever you choose — Hotels.com, Booking.com, or direct. Prefer not to install anything? You can check one hotel's price and watch it by email and get pinged when it drops.