When it comes to hotel booking sites, there’s no shortage of options these days. And while having lots of options is definitely a good thing when you’re trying to compare prices, amenities, and other hotel perks, sometimes it’s hard to know where to begin.
Are you looking for a hotel search engine with endless filters and sorting options, or an easy interface for booking hotels online? Perhaps you’re looking specifically for the best site to book hotels in Asia, or LGBTQIA-friendly accommodations.
In this list, I’m breaking down the best hotel booking sites depending on your wants and needs. And if you’re wondering what my personal favorite is, just keep reading!
- Best Hotel Booking Site Overall: Booking.com
- Best Hotel Booking Site Runner-Up: Hotels.com
- Best Website for Hostels: Hostelworld
- Best Vacation Rental Site: Vrbo
- Best Website for Hotel Deals: Skyscanner
- Best Hotel Search Engine: KAYAK
- Best LGBTQIA+ Friendly Hotel Booking Site: Orbitz
- Best Flight and Hotel Booking Site: Expedia
- Best Hotel Discount Site: Hotwire
- Best Hotel Aggregator Site: HotelsCombined
- Best Website to Book Hotels in Asia: Agoda
- Booking Site with the Best Hotel Rates: Priceline
- Best Hotel Price Comparison Site: Momondo
- Best Hotel Site for Vacation Packages: Travelocity
- Best Hotel Search Site: Google Hotels
- Best Last-Minute Hotel Deals: HotelTonight
- Best Hotel Booking App: Hopper
1. Booking.com: Best Hotel Booking Site Overall
Booking.com is the largest hotel booking site in the world. It currently has over 28 million listings, including hotels, resorts, homes, apartments, and lots of unique places to stay. Even if you’re not an avid traveler, chances are you’ve heard of Booking.com. Other hotel websites are incomparable when it comes to the number of hotel listings that Booking.com has.
Because of how prolific Booking.com is, the site is available in more than 40 languages worldwide. They have a dedicated 24/7 helpline, and an awesome low-price guarantee: if you book a property and then find it listed on another site at a lower price, Booking.com will refund you the difference…at least up to 24 hours before you check-in.
After your second booking, you automatically become a Booking.com Genius with all kinds of additional perks, like discounted rooms and upgrades. The more you book, the more you save on your next hotel stay.
And, personally, one of my favorite things about Booking.com is how customizable its search function is. You can do a broader destination search, search within a neighborhood, or really drill down and use the map function to search within a specific area. There are tons of filters as well, so you can filter by hotel star rating, included amenities, prices, or a specific hotel chain.
- More listings than any other site
- Has an excellent rewards program
- Low-price guarantee
- Incredibly customizable search functions
- The number of listings can actually be overwhelming
- The low-price guarantee is useless if you’re not avidly shopping around
2. Hotels.com: Hotel Booking Site Runner-Up
Hotels.com doesn’t have as many listings as Booking.com, but the options are still significant: they have over 300,000 properties in over 19,000 places worldwide. Like Booking.com, they don’t just sell cheap hotel rooms—you’ll find everything here from luxury hotels to hostel dorms to condo hotels.
Hotels.com really shines when it comes to their multi-level rewards program. At their lowest tier, you can unlock secret prices and you’ll earn a free night’s stay with every 10 nights you book. The there’s also Hotel.com Rewards Silver and Gold—once you’ve booked 30 nights, you’ll get free room upgrades and guaranteed late check-out or early check-in at certain properties.
Best of all, you don’t have to pay to play. You simply book accommodations and climb your way up the rewards ladder.
I highly recommend using their app. Hotels.com often features last-minute discounts with up to 40% off hotel bookings when you’re looking for a same-day check in via their app. It’s friendly to use, and worth your time to find a cheap hotel deal.
- Huge database of properties to book
- Excellent reward program that’s also easy to use
- Shows hotel star rating so you can find the best one
- Easy-to-use app
- If you want to use redeem your free nights, you have to use the app
- Not as many listings as some hotel booking sites
3. Hostelworld: Best Website for Hostels
Hostelworld has long been my go-to option for booking hostel dorms and they’ve rarely let me down. It seems like every hostel in the world is listed on this site, and thanks to this, it’s super easy to find something you like.
This is one of those cases where the guest reviews are incredibly useful. In fact, I’ll rarely book a hostel via Hostelworld without having a look at the ratings and reviews first. They’re usually spot on in their feedback and they’ll help you know what to expect before arriving.
Affordable hostel dorms shouldn’t mean dirty accommodations or noisy common areas—you still want to get good value for your money. Hostelworld’s review scores include things like security, services, location, and atmosphere, so you’ll know exactly what you’re getting.
Hostelworld’s customer service is also excellent. They’ll refund the price of your hostel if you find it elsewhere for cheaper, and you can cancel up to 24 hours before check-in without losing your deposit. I’m a big fan of Hostelworld for all these reasons!
- Seemingly every hostel in the world is listed on this site
- Guest reviews are incredibly thorough and useful
- Easy to use website
- Many of the hostels include free breakfast, which is wonderful if you’re on a budget
- Free cancellation bookings cost more than non-refundable bookings
- There are no perks or rewards as a repeat customer
- No loyalty program
4. Vrbo: Best Vacation Rental Site
Vrbo stands for Vacation Rentals By Owner, which is the fundamental difference here from hotel booking sites: you book directly from private property owners. There are no individual hotel rooms listed on Vrbo, but you’ll find just about everything else, from sprawling oceanfront condos to city apartments to mountaintop cabins.
Most people think of Airbnb for booking vacation rentals, but after doing a deep dive, Vrbo really came out on top. Although it doesn’t have as many listings, I found that Vrbo’s customer service far exceeded Airbnb thanks to its 24/7 customer support (meanwhile, Airbnb’s was basically non-existent). Vrbo also has a Book With Confidence guarantee, so you’ll get free cancellation coverage even if you cancel last minute.
Vrbo has the best deals for vacation rentals, with cheaper service fees to boot. Vrbo also isn’t subjected to extra taxes like Airbnb sometimes is. For example, in some places, Airbnb automatically collects an occupancy tax due to regulations in place to ease the burden of over-tourism (it seems like some governing bodies don’t deem Vrbo to be as big of a threat to over-tourism as Airbnb). Overall, Vrbo is my top choice for vacation rentals.
- More affordable listings than on other vacation rental sites
- Exceptional customer service
- Low booking fees
- Backed by an insurance policy for last minute cancellations
- No option to book private rooms within an accommodation
- Not as many listings as Airbnb
5. Skyscanner: Best Website for Hotel Deals
Skyscanner is most notoriously known for having the best flight deals, but did you know that they also have the best hotel prices? Skyscanner is different from other hotel sites because they specialize in cheap hotel deals, special sales, and exclusive discounts. They’re especially good at finding last-minute deals.
If you’re looking for a cheap hotel room, I recommend downloading Skyscanner’s app. You can filter search results to find hotels in your budget, or select the “Only show discounts” option. But here’s a pro tip: you can search for non-refundable rooms to find the best rock-bottom hotel prices out there. If you’re completely certain of your travel dates, this is a great option.
Another thing I like about Skyscanner: when you search for hotel stays, the search results also show the total cost for the duration of your trip (minus taxes and fees). It’s a nice way to wrap your head around budgeting for the entire trip, if you’re someone like me who enjoys crunching numbers.
- Has a reputation as one of the best online travel agencies
- Tons of filters to help you find cheap hotel deals
- Has an easy-to-use app
- You can set up price alerts to get notified when prices drop
- Doesn’t have as many hotel options as other booking sites
- Doesn’t show taxes and fees in the search results
6. KAYAK: Best Hotel Search Engine
Sometimes it’s just nice to use a simple search site with a clean, friendly interface, and KAYAK certainly has that down pat for hotels.
Unlike many sites on this list, you can’t book hotels directly through Kayak. Instead, it is just a search engine that scans through thousands of hotel chain websites, online travel agencies, and more to find discounted hotel rooms. You’ll be directed to a different site to book directly with the hotel or through a different travel website.
KAYAK actually searches for more than just hotels. You can also find flights, cars, vacations, things to do, trains, and even cruises. And yet, despite doing all that, KAYAK is an absolute pleasure to use.
Another thing I love about KAYAK: it has an excellent price predictor tool, so that when you’re searching for a hotel room (or any type of accommodation), it’ll let you know if you should sit it out for a while. Kayak uses trends for certain times of the year to predict whether a hotel room with be cheap, mid-range, or expensive. You can also sign up to get alerts about price changes.
If you want an easy way to book hotels online, KAYAK is your site.
- Simple, no-frills website
- You can book a full vacation, including flights and packages
- Has a handy price predictor tool
- You book via the hotel’s website, so you’ll collect hotel points if you’re in a loyalty program
- Sometimes the prices on the hotel website are cheaper
- You can’t book cheap hotel rooms directly on the Kayak website
7. Orbitz: Best LGBTQIA+ Friendly Hotel Booking Site
In 2021, Orbitz did a massive rebrand and decided to focus on the LGBTQIA+ market. At first glance, this seems a little gimmicky. Is this just another way to capitalize on a minority demographic? But Orbitz has dedicated a whole part of their website to LGBTQ-friendly travel, and that’s not something I’ve seen other travel sites do as well.
If you’re a LGBTQIA+ traveler, staying at an inclusive hotel might be important to you. All hotels listed on this specific section of the Orbitz website have signed a special pledge to agree to enforce a zero-tolerance policy for hateful or discriminatory behavior from any staff at the hotel. Save money, search for cheap hotels, and feel assured you’ll be staying in a safe place. Win, win!
Some hotels have also taken extra steps, like offering additional training for staff on sexual orientation, gender identities, and gender expressions. Orbitz also gives to charitable organizations that support LGBTIA+ charities.
- Offers the best hotel deals for the LGBTQIA+ community
- Hotels featured here have signed pledges to be inclusive
- Has lots of great last minute deals
- The website is super busy and distracting
- Not as good filters as other hotel booking sites
8. Expedia: Best Flight and Hotel Booking Site
When it comes to top hotel booking sites, Expedia is basically a household name. It has been around since 1996, and since forming the Expedia Group (along with companies like Travelocity, Hotels.com, and Orbitz), it’s learned a thing or two (or a thousand) about finding the best hotel deals, flights, vacations, and more.
If you need to book both flights and hotels for your trip, Expedia lets you do it all in one easy user interface. Plus, by bundling your flight and hotel reservation together, you can save a fair amount of cash on your trip.
You can test this out by searching for the specific flight or hotel, taking note of their prices, and then searching for the same together in a package (similar to booking packages with Expedia, but without the car rental). Sometimes the difference is significant—you can save up to hundreds of dollars.
That doesn’t mean you shouldn’t run a hotel or flight search on different hotel booking sites. There’s a chance you’ll be able to find better a better deal on the same hotel elsewhere, or a flight somewhere else.
- Straightforward process for reserving hotels, flights, and car rentals
- One of the longest standing hotel booking sites in the world
- Offers payment plans to help pay off your trip
- Difficult to book multiple accommodations in one package
- Like most other third party sites, it’s still a good idea to check the hotel, airline, or rental car website to compare prices before booking
9. Hotwire: Best Hotel Discount Site
Hotwire tops the charts for best hotel booking sites when it comes to secret deals and discounts. It’s a great way to find high-value hotel deals because it sells off hotel rooms that have gone unsold. Basically, hotels don’t want people to know that they have unsold rooms going for super discounted rates, so when you perform your search, you don’t actually see name of the hotel.
However, you will be able to see the hotel reviews, ratings, neighborhood, amenities, and TripAdvisor ratings, as well as the exact hotel the person before you booked (for example, “The last person got the Holiday Inn Toronto Downtown Centre”). If you’re not super picky about where your hotel stay is located, then is a great option.
Plus the mystery of it all is kind of exciting, isn’t it?
Hotwire also has an excellent map view, and although this is typical of most hotel search engines, this one is particularly using for honing in on the location of your particular hotel without actually knowing what the hotel is. You can also find cheap hotels by filtering by price point and other options.
A word of warning, however: sometimes the price advertised in the search results isn’t the cheapest. Although I booked and paid for a hotel in Boston via Hotwire, the hotel accidentally charged me for the room when I checked out. The price difference was actually cheaper directly with the hotel! When I complained to Hotwire, they reimbursed me the difference immediately. But the whole thing was a little bit shady.
- Offers the best deals on secret, high-end hotels
- Hotels don’t want you to know they’re selling off their unsold rooms, so you’ll get highly discounted rates
- The mystery of it all is just plain fun!
- Doesn’t have a rewards program for frequent travelers
- Sometimes it’s cheaper to book directly with the hotel
- You might be disappointed with your hotel stay
10. HotelsCombined: Best Hotel Aggregator Site
HotelsCombined is an aggregator, which basically means it scours multiple hotel booking sites at one time to bring you the best hotel deals. HotelsCombined claims to search hundreds upon hundreds of hotel booking sites, including some of the top hotel booking sites like Agoda and Hilton, and some smaller ones that are lesser known.
But you don’t actually make a hotel reservation on HotelsCombined. Like other third party sites, HotelsCombined takes you to the actual hotel booking site, like Expedia or Hotels.com, where you’ll complete your booking. It’s a great way to compare prices across the board.
However, despite the multiple booking sites it searches, sometimes you’ll find better hotel deals on other hotel booking sites. You’ll have no problem finding super cheap hotel stays, but if you want to have a look at all your options, it’s best to search some other hotel reservation sites as well. For this reason I don’t often use HotelsCombined to make a booking, although I have certainly used it for comparing hotel prices.
- As a metasearch engine, HotelsCombined scours hundreds online travel agencies and booking engines at one time
- You can see prices with or without taxes
- Easy to use and compare pricing and hotel reviews
- Seems to miss a lot of hotels, properties, and even rooms that other hotel booking websites have listed
- Lots of ads all over the website makes for too much clutter
11. Agoda: Best Website to Book Hotels in Asia
Agoda originally started in Singapore, which means they started out strong as the best website for hotels in Asia and has managed to maintain that reputation ever since (even now, as they’ve grown to offer accommodations, flights, and more worldwide). Agoda is practically a household name in Asia, and is the largest online travel agency in some Asian countries. Whenever I’m traveling in Asia, I always start with Agoda.
Like other hotel booking websites, Agoda also offers accommodations in homes and even hostels. If you desire a pod hotel in Japan or a city apartment in the middle of Bangkok, you’re in luck. There are lots of options!
Agoda also has an excellent secret deal program where the identity of the hotel remains anonymous until your booking is complete. You can see things like the star rating and the neighborhood it’s located in, but not the actual hotel…until after the reservation is made. This is so higher-end chains can sell off their rooms without letting the public know how cheap they’re going for.
Finally, there’s a PointsMAX program that lets you align your Agoda account with your mileage program, including the likes of American Airlines AAdvantage and KLM/AirFrance Flying Blue. I’ve found this to be a rarity amongst hotel booking sites, which is why I consider Agoda one of the best websites out there for finding and reserving hotels.
- Specializes in Asia properties
- You can earn rewards with your other loyalty programs, including mileage programs
- Has secret deals you can unlock
- Insider deals aren’t always the best option—you’ll have to shop around
12. Priceline: Booking Site with the Best Hotel Rates
Priceline started out with a simple concept: if airlines regularly flew while only half full, and if millions of hotel rooms were going unused every night, what if other travelers could fill up these empty spaces with discounted fares? After all, every bit of profit counts.
In my opinion, Priceline really stands out with their Best Price Guarantee policy. When you become a Priceline member, you’ll have access to the site’s Express Deals, which are pre-paid, non-refundable, and non-transferable.
If you find a better price on an Express Deal up to midnight before you travel, you’ll be refunded 200% of the difference in price!
Even if you make a booking that isn’t an Express Deal, you’ll still get refunded the difference if you see a better price within 24 hours of booking your hotel room. Priceline also lets you search for hotels, rental cars, plane tickets, and cruises. It’s an excellent comprehensive site for anyone who knows their exact travel dates.
- Incredible price match guarantee
- Great last minute prices on hotel deals
- One of the easiest to use hotel websites
- Trips are non-refundable and non-transferable, which doesn’t allow much room for flexible travel
13. Momondo: Best Hotel Price Comparison Site
Momondo is a pleasure to use, and is one of the best search engines out there for hotels. The website itself is clean, sharp, and attractive—and best of all, everything is completely transparent.
When you search for properties on most hotel sites, you’ll get an aggregated list of hotel deals but not many other details. When you use Momondo’s hotel finder, you’ll get a comprehensive price comparison.
For example, a search for hotels in Krakow, Poland, brings up a list of hotels with their lowest price listed. City Light Apartments shows four different prices: both Expedia and Hotels.com have the same lowest fare, but Booking.com and eDreams are much higher in cost. Im not even familiar with eDreams, so it’s nice to see that Momondo gives options that are beyond the regular top 5 booking sites.
I absolutely love that Momondo breaks everything down in such a succinct manner. You can also use it for your next trip to book flights, car rentals, activities, and packages.
- Simplistic search results
- Offers up several price comparisons
- Searches sites that aren’t as common as the leading brands
- Lots of filter options
- You’ll be booking through a third party site, so it’s important to understand their cancellation policies before you commit
14. Travelocity: Best Hotel Site for Vacation Packages
Who else can’t hear the name “Travelocity” without thinking of the little blue gnome? That’s some good marketing! Like many of the other hotel sites mentioned here, Travelocity gives you options for booking flights, hotels, rental cars, cruises, and more. And when you combine your trip reservations, you can save a fair amount of money.
I find that Travelocity is especially useful for booking vacation packages, which is not something I often do but is sometimes just a wonderfully convenient way to plan a trip. The process is extremely straightforward, with the option to first book your hotels, and then your flights and rental car. In a matter of minutes, you’ll have a whole complete package booked.
On the other hand, Travelocity seems to assume you’re going to fly into one city and spend your whole time there. While you have the option of booking a hotel for only part of your trip, if you’re planning on road-tripping around, you’ll have to book hotel rooms in other places separately. It’d be nice if they offered a way to book multiple hotels per vacation package.
If you register an account, you’ll also be offered lower up rates of 10% or more on select hotel reservations.
- You’ll save money on booking your entire vacation together
- Comes with a price match guarantee
- Discounted hotel rooms at certain locations if you’re a member
- You can set up price alerts
- The lowest price for the bundled flight and hotel room doesn’t necessarily mean you won’t find it cheaper elsewhere
15. Google Hotels: Best Hotel Search Site
Google doesn’t actually have its own hotel booking website, but seeing as how Google is the most powerful search engine in the world, it should come as no surprise that you can now find cheap hotels directly from Google Hotels search.
It’s surprisingly smart—you can easily narrow down all your hotel options by searching for specific things directly in Google. For example, if you’re searching for hotel locations within walking distance to a conference you’re attending, all you have to do is Google hotels “near Austin Convention Center” and you’ll get a whole list of options plotted on Google Maps.
From there, you can click “View more” on the search results and filter out some of the hotels around the area you’re most interested in staying. All the hotels are plotted on Google maps, alongside other sites of interest like museums, statues, and restaurants.
The search results show plenty of great options, and you’re able to filter out your preferred hotels to find the best location for you. However, the results show just hotels and no other kinds of accommodations like vacation homes or shared spaces (except maybe some hostels). If you care more about the location of your hotel over finding cheap hotels, Google search results is an ideal option.
- You can really narrow down the best location to stay in
- Ideal for business travelers
- Easy to use filters and sorting options
- Not always the best price
- Limited types of accommodations available
- No option to book directly on Google
16. HotelTonight: Best Last-Minute Hotel Deals
If you’re a spontaneous traveler who doesn’t mind booking reservations last minute, you’ll love HotelTonight. This same-day booking app helps you to find highly discounted rates, even at peak vacation times. If you’re wingin’ it and booking hotels last minute, this is a great option for you, with discounts averaging between 30-50%.
All the hotel listings are categorized based on their luxury offerings and amenities, as well as price range. You might see boutique hotels labeled with DEAL, meaning the savings are significant. Other hotels are categorized as LUXE, HIP, BASIC, SOLID, and other buzz-worthy words. For example, Luxe means a high-end hotel, Hip refers to popular and trendy hotels, and Crashpad means hostels and budget rooms.
HotelTonight definitely caters to a certain demographic. One of their key messages is “Happy hour is never just a happy hour.” I suppose it’s a good tactic to discourage people from drinking and driving, but it’s a little bit sleazy at the same time. I feel like HotelTonight is expecting you to have the app handy in case there’s an emergency one-night-stand.
Even if you can’t find the ideal hotel deal, you can still request upgrades at discounted rates, which not many hotel booking sites seem to offer. HotelTonight is also purely a hotel booking website—you can’t book anything else here. It’s kind of refreshing.
When signing up, use the HotelTonight promo code JFOSTER237 to get 20% back (up to $50) after your first booking.
- Same-day bookings lead to excellent rates
- One of the few hotel sites that has discounts on upgrades
- Booking hotels is easy and straightforward
- Only works well in large cities, mostly in the United States
- Doesn’t have as large of a database as other discount hotel sites
17. Hopper: Best Hotel Booking App
It seems like there’s an app for everything these days, including hotel reservations. Hopper is one of the best apps in the world for booking hotels. The company originally made a name for itself as a flight search engine, and since then has moved on to hotel bookings as well.
Hopper uses special software to predict future hotel and flight prices. If you’re skeptical about that, Hopper claims that their predictions have 95% recommendation accuracy! And after using them in the past to track both hotel and flight trends, I’d have to agree with them. They’ll notify you immediately if there’s a deal for the hotel you want, which is ideal if you’re planning a trip for the future.
Hopper also has a unique Price Freeze option for your hotel. If you’re researching your trip in advance and you find the best deal you’ve ever laid eyes on, Hopper will allow you to hold onto that deal for up to 60 days.
To lock in the price, you’ll have to put down a deposit (a percentage of your stay), and if the price goes up during those 60 days, Hopper will cover the difference up to $100. If the price goes down, you’ll pay the cheaper price.
You can even transfer your deposit to another hotel if you decide not to stay there. How’s that for customer service?
- You can track deals over time and follow price trends
- Their Price Freeze option locks in your deal for up to 60 days
- Predicts rates and trends with a 95% accuracy
- Lets you set up price alerts to see when prices drop
- You can only carry out your flight or hotel search on the Hopper app
Best Hotel Booking Sites FAQs
What is the best website to look for hotels?
With that being said, there are so many websites that consider themselves amongst the best hotel booking sites, but the truth is, the competition is fierce. Furthermore, many of these sites belong under the same umbrella: Expedia Group doesn’t just include Expedia, but also other major sites like Vrbo and Hotels.com. While each has something different to offer, chances are many of the prices and deals are the same.
But I’ve also used Hotwire and HotelTonight when my flight has been cancelled and I’d rather not spend a night in the airport. I use Hostelworld when I’m backpacking and Hopper when I’m planning far in advance.
What is the cheapest way to book a hotel?
I think the best way to look at booking the cheapest hotel room is to consider the value of your stay, rather than the amount you’re spending. For me, that means a comfortable room with lots of amenities near a busy city center or public transit. For you, it could be completely different.
If you’ve considered all the hotel sites in this article, by now you should have a good idea of what kind of hotel websites will suit your needs. You should always search a number of sites to compare all their prices if you’re interested in finding the best deals.
However, other factors make a difference as well. If you’re traveling in peak season, prices will be higher. If you want a hotel room smack dab in the middle of a busy city center, you’re going to pay a lot more.
How do I get the best deals on hotels?
To get the best deals on hotels, always dive a little deeper into the booking website and see what they have to offer. For example, if you use Hotels.com‘s app, you’ll automatically access better deals that are only featured exclusively on the app.
The same goes for rewards and loyalty programs. Companies like Expedia and Hotels.com reward loyal members by offering discounted rates and even free hotel stays. And they’re nearly always free to sign up for.
Is it cheaper to book a hotel on their website?
Sometimes it is cheaper to book a hotel on their website. And, sometimes, a hotel will offer free upgrades or bonuses (like free breakfast) when you book directly with them. This is because they won’t have to pay a commission to the online travel agency.
Also, if you’re a member of a loyalty program for a certain hotel brand (like Marriott), it’s always best to book direct via the website. Many hotels do not honor the loyalty program if you book via another site.
Is Airbnb cheaper than hotels?
Airbnb tends to be cheaper than hotels because you will be booking directly from a private property owner rather than a legit business.
Airbnb is really great for group travelers and anyone who wants to book out a full vacation home rather than a room or a shared space, as you can split the cost with other people (and find some pretty unique accommodations in the process).
However, in my review of Airbnb vs Vrbo, I’ve found that Vrbo is actually a better choice for finding a vacation rental. Service fees are cheaper, their customer service is much better, and often the price listings were much lower.
Final Thoughts on the Best Hotel Booking Sites
Although I certainly have some strong preferences for best hotel booking sites, my strategy is to compare prices on hotel comparison sites and make a decision from there. I usually start with Booking.com, as they have the most options, but I’ll check a few other sites as well.
I’ll also always check the actual hotel website to see if better rates or upgrades are offered there. I use Hostelworld to book hostels (although I’ll also sometimes check the hostel website for comparing hotel prices), and Vrbo to book vacation homes.
Explore your options, figure out which websites you like the most, and go from there. Sometimes the user experience is just as important as finding great deals. Happy hunting!