KAYAK

Is KAYAK safe to use?

Yes, for comparing prices: KAYAK has no reported breach of user accounts, pays outside researchers to find security bugs, and in most cases never takes your money itself. It searches hundreds of sites and sends you to the airline, hotel or agent to pay. The trade-off is data. KAYAK shares what you book and browse with advertising partners for their own marketing, and in 2025 its parent paid Texas US$9.5 million to settle a hidden-fee case that named kayak.com. We score KAYAK 60/100.

What KAYAK shares, and with whom

Apple's label is fairly short: user ID, device ID, product interaction and advertising data are listed as used to track you across other companies' apps and websites. Linked to you for KAYAK's own marketing, analytics and personalisation are precise and coarse location and your email address. Google Play adds that payment info, email and phone are shared with other companies to complete bookings, and device IDs and app interactions for advertising.

The privacy policy, in force since July 2024, goes further. KAYAK says it shares information with "other third-party business partners for their own marketing purposes", including advertisers and ad tech firms, and that this covers your bookings for flights, hotels and cars plus cookie data about the sites you visit and what you search for. When you ask to book through KAYAK, the travel partner receives your name, contact details, passport and frequent flyer details and itinerary, and also your "travel activity and history", which it may use for its own targeted advertising.

KAYAK is part of Booking Holdings, and data flows across the group: single sign-on across brands, and your Booking.com and OpenTable reservations shown in your KAYAK account. The good news is that the policy gives you real switches. Account preferences let you opt out of each kind of sharing for marketing: group companies, travel partners and other business partners.

Hidden fees and the Texas case

In 2023 the Texas attorney general sued Booking Holdings under the state's Deceptive Trade Practices Act. The petition said the company's sites, listing booking.com, priceline.com, agoda.com and kayak.com, all showed hotel rates without mandatory fees, which appeared only at checkout, often folded into a "Taxes and Fees" line. On 19 August 2025 the attorney general announced a US$9.5 million settlement, the largest a state had recovered over hotel "junk fees", under which Booking must disclose added fees up front.

The settlement was with the parent company, not KAYAK alone, but the suit named kayak.com, so we count it in KAYAK's record. For you, the practical lesson is the same on any price-comparison site: compare totals, not headline nightly rates.

Partners, Hacker Fares and the cheapest price

Most of what goes wrong after a KAYAK search happens on someone else's site: an agent whose final price is higher than the one KAYAK showed, slow refunds, or customer service that is hard to reach. KAYAK shows which company is selling each fare, and it is worth checking before you click.

Hacker Fares are KAYAK's own invention. A Hacker Fare is a round trip made of two one-way tickets, sometimes on different airlines and sometimes into one airport and out of another. KAYAK labels them and warns that baggage allowances may differ on each flight and that you may need proof of onward travel at the border. Because they are two tickets, a cancellation or schedule change on one airline does not oblige the other to help you.

Security

KAYAK has run a public bug bounty on HackerOne since April 2022 and pays researchers for valid reports; 546 have been resolved. Its security page says it follows the NIST Cybersecurity Framework, has a round-the-clock security operations team, encrypts data at rest and in transit, keeps personal data and card data in separate environments, and has outside firms run penetration tests every year. We found no reported breach.

How to use KAYAK more safely

1. Check who is selling a fare or room before you click through, and prefer the airline or hotel itself when the price is close.
2. Compare the total price on the partner's checkout page with the KAYAK result, and go back if it has grown.
3. Before booking a Hacker Fare, check each airline's baggage rules and your plan if one flight changes.
4. In your KAYAK account preferences, opt out of sharing with group companies, travel partners and other marketers.
5. Pay by credit card so you have a chargeback route if a partner fails to deliver.

How we scored it

Security (72) is the strongest factor, thanks to a paid bug bounty, independent tests and no breach on record. Privacy (45) is the weakest, because KAYAK shares bookings and browsing data with ad tech firms and travel partners for their own marketing. The regulatory record (66) carries the Texas settlement. Skyscanner, a similar price-comparison app, scores 63 and Booking.com 47.