Best UK Online Slots (Top-Rated Casino Games)

There are many online casinos available in the UK and players are always looking for classic and new exciting online slots to play. Here at CasinoTop, our team of experts have reviewed hundreds of real-money online casinos that offer some of the best online slots out there.

The online slots in the UK at these top online casinos are developed by some of the best software developers in the gaming industry. We have done all the groundwork so that you don’t have to. The best online casinos offering the best online slots have been put into a list of recommended online casinos for you to easily choose from and that suits your needs perfectly.

Top-Rated Online Slot Casinos in the UK 2023 

100% match bonus up to $150
1 to 2 days Payout
96.68% Win Rate
500 Free spins
1-5 days Payout
Win Rate
1-7 Days Payout
96.8% Win Rate
1 to 5 Days Payout
98.1% Win Rate
Win Rate
1-7 days Payout
71% Win Rate
1-2 days Payout
97.21% Win Rate
1 to 5 Days Payout
90% Win Rate
1 to 2 Days Payout
96.35% Win Rate
1-2 Days Payout
96.35% Win Rate

Blacklisted Online Casinos for Slots in the UK

Through our journey of reviewing online casinos and finding the best online slots for you, at times we come across sites that we recommend you avoid. Our review process takes into consideration the website’s user interface, bonuses and promotions, banking methods, security, mobile accessibility and more.

If these online casinos do not meet the high standards that we have set, then the online casinos will find their way onto the following blacklist. Our team often revisits the online casinos offering online slots in the following list. If they improve their criteria then they might find their way off the blacklist in the future.


Incorrect and misleading marketing relating to safety measures
Confusing wagering requirements
Inferior quality of games displayed


Customer complaints remain unresolved
Unprofessional customer service received
Stalled winnings being paid out


Consumer complaints ignored
Misleading claims to proper international licensing
Improper online casino practices in use

Online Slots with the Best Payouts in the UK

Our team of experts take their time to test the online slots at the best online casinos. We take our time and try the games out as well, so we can provide an informed report for you to use. Here are some of the online slots available in the UK that offer the best payout percentages.

Rank Casino Bonus Offer Nuber of Games
#2Avalon IIMicrogaming97%
#3Guns N' RosesNetEnt96.98%
#4Thunderstruck IIMicrogaming96.65%
#5Wheel of FortuneIGT96.46%
#6Mega FortuneNetEnt96.6%
#8Gonzo's QuestNetEnt96%
#9Book of RaNovomatic96%
#10Wizard of Oz WMS95.99%

Types of Online Slots in the UK

There are many different types of online slots available to players these days. Having the slots presented online allows operators to add more games as often as they can and not have to worry about physical space. In the sea of online slots, you will find online slots that are developed differently and offer simple to complicated gameplay. Here are the main types of online slots that you will find at the best online casinos in the UK.

Three-Reel Slots
Multi-Reel Slots
Video Slots
Progressive Jackpot Slots

Three-Reel Slots

The simplest and oldest form of slot games. The three reels usually have standard symbols such as playing cards or fruit. The paylines are also simple and all you need to do is get a set of matching symbols in a row to form your winning combination.

Multi-Reel Slots

These slot games were created later and usually feature up to five reels, sometimes more. The paylines in the game can range from 25 simple paylines to more than 100 paylines. The latter occurs when the set paylines go in different directions as the line makes it to the other side of the reels.

Video Slots

These slots offer more of a story to tell players. Certain combinations and symbols can result in players earning in-game bonuses, unlocking bonus levels and games and even unlocking additional reels as well as some new symbols. It usually comes packed with 3D animation to make the gaming experience more immersive. Video slots shine at online casinos and there are so many to choose from.

Progressive Jackpot Slots

This game is played often by tons of people at online casinos. A progressive jackpot slot can exist on its own and a portion of every winning bet will be added to the total jackpot until a lucky player strikes the ultimate winning combination to win the jackpot. In some cases, the same game can be found on different online casinos which are linked to each other, which helps grow the overall jackpot even bigger. Players that win progressive jackpots often have their lives completely changed by the millions they win at an online casino, just by spinning the reels.

The Best Bonus for Online Slot Casinos in the UK

Any reputable online casino will offer players a welcome bonus to get them in the door. This also helps the player get accustomed to the website and the online slots available. In most cases, online casinos will offer players bonus cash, which amounts to a percentage of their first deposit. However, the online casino could also include free spins to use with online slots.

Use our bonus calculator to find out which online casino best suits your deposit amount. Finding an online casino that offers a lucrative bonus, with reasonable or low wagering requirements is the best outcome. This means that you have a better chance of turning free bonus cash into real money, a lot quicker.

Bonus Calculator

By working out the value of bonus, you can determine how much you can play with in both your deposit and bonus money.

Depending on the value of your enter as a deposit, you'll see that some casinos will offer you the best bonus based on your first deposit while other casinos may require more than one deposit to receive the offer.


Casinos award bonuses based on the total bankroll figure. You can unlock the same bonus at different casinos, but it depends on whether you are required to make one, two, three or more deposits to receive the best option for you. Casino - Logo
Ignition Casino - Logo
Red Dog Casino - Logo


Use this tool to compare bonuses at different online casinos and stick with the casinos that have the fairest wagering requirements. Always make sure to read the T&C before accepting a bonus.

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Offerings From the Best Online Slots Casinos in the UK

The online casino landscape has grown really quickly over the past few years. With that growth, online casinos have invested a lot into the work that software developers are doing to create more titles. Gone are the days where you needed to account for how much space you had on the casino floor and that determines how many games you can have. Here is how online casinos offering online slots can change the way you see slot games.


Secure and Reliable Software

The most trustworthy online casinos will have a great selection of games that are packed with the best software. Software developers like Microgaming, NetEnt, Playtech, Push Gaming and others take their time to produce quality gaming experiences. These have the best graphics and most video slots tell their stories really well. These online slots are sure to function perfectly on your desktop computer or a mobile device of your choice.

Online casinos also ensure the safety of your money and personal information. This is especially true when the online casinos offering online slots have a license from a reputable source and are also regularly audited by companies such as eCOGRA.

Huge Selection of Games

The online casinos we recommend for playing online slots all have hundreds if not thousands of online slots to choose from. Players will find three-reel and multi-reel online slots at these online casinos. The games are made even more exciting when you can find a game you like in a specific genre or theme. We also take our time and find online casinos that offer free to play games as well. You can test out an online slot for free before you commit to depositing real money and placing a bet.

Great Welcome Bonuses

One of the most important things we check for is what the online casinos are offering as a welcome bonus. We want players to have a warm welcome when they choose a site from our list. We want to see free spins, match bonuses that can be used on slots and payout percentages that are 90% or higher. There should be a high chance for the player to win each time they spin the reels.

High-Quality Gaming Experience

The online casinos we review along with the online slots they have on offer, need to fit the criteria above or exceed it. That is the only way for an online casino offering online slots to find its way onto our list of recommended online casinos. When you choose from that list, you can rest assured that you will receive premium quality entertainment that is safe and can be enjoyed through several operating systems. We also come back every few months to ensure that the online casinos are maintaining their standards or exceeding them.

Free Online Slots Vs. Real Money Slots

Free online slots are a great way to kill time and play your favourite online slots without any risks. However, any slot enthusiast will tell you that the thrill comes from taking that risk. Here are some of the pros and cons our team have found about these two versions of the games.

Free Game Online Slots
Test-drive online slots before taking risks with real money
No sign-in or account creation to play
Access free games directly from your internet browser
No personal information is required to start playing
No real-money winnings at the end of it all
Casino bonuses cannot be used on free-to-play online slots
Real Money Online Slots
Chance to play and win a progressive jackpot
Take advantage of the welcome bonus, ongoing promotions and loyalty programs
The chance to win real money prizes are really high
Withdrawals take a few business days to process
Players stand a chance of losing money as well

Strategies for Online Slots

It's not realistic to think that there are actual strategies that can be used when playing online slots. These games are governed by Random Number Generators to ensure that they are fair and random at all times. This also ensures that anyone stands a chance to win and all it takes is luck. However, avid online slot players swear that playing games with the highest payout percentages, knowing their paylines and practicing bonus rounds are sure ways to win.

Payout Percentages Explained

When you get used to doing your research about online slots, you will always see experts referencing the payout percentage of a game or the return to player rates (RTP). These figures tell you a lot about your chances of winning and the house edge. If an online slot or slot machine has a payout percentage or RTP of 98%, that means that the operator or casino pays out £98 for every £100 that is bet on the game. We ensure that these figures are clearly displayed for you, so you can decide if it is worth playing the game or not.

Online Slot Software Providers in the UK

There are thousands of online slots at online casinos. However, some of the most impressive gaming features come with video slots. The software developers that create these games do a great job of bringing an exciting gaming experience to life. These software developers are well-known in the industry, but here are some of the developers we think you should look out for when looking for an online slot game to play:

Real Time Gaming
Merkur Gaming

Play Free Online Casino Games

View All Free Games

Our list of the best online casinos in Canada contains offerings from operators that are dedicated to varied and safe entertainments. Canadian players can enjoy a wide variety of free gaming options from some of the most popular genres. This means that there are free to play modes for traditional table games such as poker, roulette and blackjack.

Online Slots in the UK FAQs?

Are there free online slots I can play?

If you are not ready to place real money bets with online casinos playing online slots then there are tons of options available that you can play for free. We check to see that the recommended online casinos in our list all have free to play options when it comes to online slots. You can experience all the fun that an online slot offers without taking any risks.

What should a good online casino have that I should be looking for?

Any reputable online casino that offers online slots should be fully licensed by one of the most reputable online gaming authorities. These include the UK Gambling Commission, the Malta gaming authority or a license from the government of Curacao. You should also be looking for a favourable payout percentage. The higher the payout percentage is, the more you stand to win if you get a winning combination.

Do online slots have real money prizes?

Yes. You can win real money at an online casino the same way you would at a land-based casino with a slot machine.

Are online slots safe?

Yes. This is especially true if you choose an online slots casino from our recommended list of sites. As long as the website is trustworthy then the game itself should be as well.

Are online slots fair?

Yes. These games are not rigged and run on RNGs or random number generators. This is software that ensures that all outcomes are exactly as they would be on a real slot machine. This keeps the game random and the chance of you winning is the same as the next player. To make sure of this, check to see if the online casino is regularly audited by an independent company that ensures the software is performing as it should.

What are progressive jackpot online slots?

These games build up a huge jackpot that is gathered from any winning bet that previous players have had. Sometimes it is a single game on a website or a game that can be played at various websites. The same game is linked through the websites and the jackpot grows faster and higher in no time.