Short answer: Hotel Ninja is a free hotel price comparison tool that works right on top of Booking.com, Expedia, Hotels.com, Agoda and other supported booking sites. Open a hotel, pick your dates and guests, and it shows the final checkout price for the same room on the other sites, with taxes and fees included. No separate comparison website, no account.
Most of us start a hotel search on Booking.com or Expedia. They’re familiar, easy to use and have a gazillion hotels. The tricky part is knowing whether the price you’re looking at is actually the best one. The same room can be noticeably cheaper on another site at the exact same moment, and nobody’s going to tell you.
That’s why we built Hotel Ninja. Instead of making you leave for a separate comparison site, it lives on the page you’re already using and checks other sites for you.
One hotel price comparison tool, many booking sites
Hotel Ninja is a Chrome extension that works on several big booking sites. When you open a hotel on a supported site, it picks up:
- Which hotel you’re looking at
- Your check-in and check-out dates
- How many guests you’re booking for, including kids’ ages
- The room type you selected
Then it checks the same room and dates on other booking sites and shows you a list of sites with their final prices. You never leave your page or repeat your search.
Keep your favorite booking site
Maybe you love Booking.com for its maps and filters. Maybe you’re loyal to Expedia for the points. Maybe Agoda just has better options in Asia. Hotel Ninja doesn’t ask you to break up with anyone. It’s a sidekick, not a replacement.
Here’s the routine:
- Start on the booking site you already like
- Search for hotels in your destination
- Open a hotel that looks good
- Let Hotel Ninja compare prices
- Check the comparison pop-up before you book
If your favorite site has the best price, book there with a clear conscience. If another site is cheaper for the same room, click through and book there. You decide where to book. We just make sure you have the facts.
Compare final prices, not teaser rates
Real hotel price comparison means comparing what you’ll actually pay. Some sites show a low base price and add taxes, resort fees or service charges on the last step. Others include more up front. Comparing the first number you see on each site is like comparing menu prices before tax and tip.
Hotel Ninja shows the final checkout price on each site, with taxes and fees included, side by side in one pop-up. So you’re not comparing headline offers. You’re comparing what actually comes off your card.
One honest note: a city tax that the hotel collects when you arrive isn’t part of any site’s checkout, so it isn’t shown. Check the “pay at property” line in the booking details for that.
Same room, same guests, fair comparison
Comparing hotel prices only works if you compare the same room. When you do it by hand, it’s easy to end up with a standard double in one tab, a non-refundable economy room in another and a superior room with breakfast in a third. Three prices, three different products.
Hotel Ninja matches the room type and guest count you picked. Booking a standard double for two adults? It compares standard doubles. Picked a family room or a suite? That’s what it looks for on the other sites. The comparison reflects your real booking, not the cheapest room in the building.
You can also filter results by free cancellation and by meal plan (breakfast, half board, full board or all-inclusive, where supported), and see an average review score based on verified reviews only.
How to use it
- Install the free Chrome extension from the Chrome Web Store
- Go to Booking.com, Expedia, Hotels.com, Agoda or another supported site
- Search for your city and dates
- Open a hotel’s page
- Give Hotel Ninja a moment to check the other sites
- Look at the pop-up with prices from different booking sites
- Click through to the site with the best final price
You don’t have to remember to switch it on. Install it once and it shows up on its own when it has something useful for you.
Who it’s great for
- Frequent travelers and digital nomads. If you book often, small differences add up over a year. Got a hotel link from a blog or an Instagram account you follow? Just open it, and Hotel Ninja shows you if it’s the best price. No need to search again.
- Families and groups. Room types and prices vary a lot when you need space for three, four or more people. Hotel Ninja keeps track of your guest count and compares rooms that actually fit you.
- Business travelers. Got a hotel link from your company? Check in seconds whether the same room is cheaper on another site, without making extra work for your travel team.
No account, no personal info
Hotel Ninja doesn’t ask you to create an account, remember another password or hand over personal information. It uses the hotel details and dates on your screen to check prices, and you finish the booking directly on the site you choose. Your payment details never go through us.
Frequently asked questions
Is Hotel Ninja free?
Yes. Hotel Ninja is a free Chrome extension. There’s no account and no sign-up.
Which booking sites does Hotel Ninja work on?
Booking.com, Expedia, Hotels.com, Agoda and other supported booking sites. Open a hotel on one of them and Hotel Ninja compares the same room on the others.
Does Hotel Ninja include taxes and fees?
Yes. It shows the final checkout price on each site, with taxes and fees included. A city tax collected by the hotel on arrival isn’t part of any site’s checkout, so it isn’t shown.
Do I book through Hotel Ninja?
No. Hotel Ninja shows you the prices, and you book directly on the booking site you choose.
Install the extension, open your next hotel on Booking.com, Expedia, Hotels.com or Agoda, and see at a glance which site really has the best price for your room.


