Slot sites are among the most popular casino websites on the planet.
However, because there are so many top slot websites it can be tricky knowing which are the best ones for you to invest your time and money in.
That’s why OnlineCasinos.co.uk has reviewed all the UK’s best slot sites.
We’ve played the games, checked the bonuses, found out what the payouts are, and assessed all the other things that you care about.
All you need to do is read through our guide, decide what the best casinos are for you, then head over to the websites and play their great slot games.
Why play online slots?
Online slots offer you the fun of a land casino fruit machine from the comfort of your home or phone. You can play them wherever and whenever you want to, without worrying about needing to visit a physical casino or its opening hours — you’re the master of your gambling sessions, not the casino.
Convenience is one of the biggest appeals of playing slots online. The very best gambling sites are available on all devices, so you can decide whether you play on your phone, tablet, laptop or desktop.
This is a huge bonus that land casinos can’t compete with but it’s not the only thing online slots offer that you can’t get from a bricks and mortar casino. A huge benefit of playing slots online is that it’s easier for you to refer to the strategies and rules of the game while you play.
There’s a simple reason that it’s easier to check the strategies and rules of online slots than it is to do the same thing at a land casino: you can use more than one screen at once.
Using multiple screens when you play online slots means you could have one for your gaming session, one to peek at the rules and one to look at your gaming strategies. This could save you valuable time during your gambing sessions, enough to be the difference between winning or losing.
So, if you want a gaming experience that’s convenient and gives you the time to really think about the decisions you make, try online slots at one of the UK’s top online casinos.
How OnlineCasinos.co.uk reviews the best slot sites
Credit: Pikist
OnlineCasinos.co.uk is a team of gambling enthusiasts who love to play casino games.
This means that we want the same things that you do from the slot sites we bet at:
Great games
Real bonuses
Competitive payouts
Safe and user-friendly site
Brilliant app
We begin by looking for gambling regulatory icons on websites, so that we know that the site can be trusted to look after your sensitive data.
Once we know a site is trustworthy, we check to see how many games you can play on both the website and app. And we play the games too, so that we can be sure that you’ll get a great experience from the slot sites we’ve recommended.
We’re very proud of our review process. Not just because we spend huge amounts of time testing the casinos and detailing our thoughts, but because we know that we’re recommending great slot sites to our fellow players – that’s you.
How can I find a safe slot site?
Credit: PeakPX
The first thing any gambler should expect from the top slot sites is that they are able to have fun. The next thing they demand is that the site is safe
You can confirm that you’re gambling at a safe website by looking for the icons of licensing and legislation organisations.
Any slot site that operates in the UK has to be regulated by certain gambling organisations and national authorities, even those that are registered outside of the UK – like in Sweden, Malta, or Gibraltar.
Slot sites want their players to know that they’re safe to use and the way they confirm this is by putting the icons of gambling regulators on their websites. There are some key icons you need to look for and these are the most important ones.
Gambling organisation icons to look for at slot sites
UK Gambling Commission
Credit: Gambling Commission
Any slot site that is allowed to operate in the UK is ultimately regulated by the UK gambling commission.
Government of Gibraltar
Credit: Wikipedia
If a slot site is licensed in Gibraltar then you’ll know this to be the case by the Government of Gibraltar logo on its website.
Malta Gaming Authority
Credit: Malta Gaming Authority
If a slot site is licensed in Malta somewhere on its website you’ll be able to find the logo of the Malta Gaming Authority.
Spelinspektionen
Credit: Spelinspektionen
You’ll know if a slot site is licensed (or able to operate) in Sweden because the Spelinspektionen logo will be displayed on its website.
Responsible gambling icons to look for at slot sites
We’ve been clear that fun is the main reason you should gamble and you should never lose sight of this, rather than focussing on whether you win or lose – even the best gamblers can lose and even the worst ones can win.
How you measure fun is up to you.
You might decide that fun looks like lots of brightly coloured slots, or you might decide that it looks like a slot game with a competitive RTP. But the key is that you gamble responsiblyby doing things like making sure your bonus funds are separate from your own personal cash, so you always know how much money you’re betting.
UK slot sites want their gamblers to know that they have a commitment to responsible gambling and they do this by putting the icons of relevant organisations on their websites.
These are the responsible gambling icons you should look out for on slot sites:
GamCare
Credit: GamCare
GamCare is a UK charity that offers support to people who believe they have a problem with gambling. It’s an organisation that people can speak to and seek the support that they need.
GAMSTOP
Credit: GAMSTOP
GAMSTOP is a self-exclusion organisation that allows gamblers to block themselves from slot sites and other betting websites.
People can contact GAMSTOP and register their intent to self-exclude from a specific site for a set amount of time. This means that during this timespan the person will be blocked from using that site by the site itself – it’s like they have a temporary ban.
You can contact GAMSTOP to find out if your preferred slot sites offer self-exclusion.
What are the different sort of slots that I can play?
Credit: Pikrepo
The top slot sites have hundreds, even thousands of different games you can play.
Video and retro slots are often the most popular slot titles at these sites. However, they aren’t the only options available to you because there’s a selection of different slots you can play.
These are the key slots you can choose:
Progressive jackpot slots
Credit: PlayOJO Casino
Progressive slots increase in value each time you wager some money on them. This means that you have the potential to really boost your winnings.
One thing to note about progressive slots is that they’re often highly volatile.
So, while you can earn larger wins from these games, you can find that you need to make lots of bets before getting close to the jackpot.
Real money slots
Credit: LeoVegas Casino
Real money slots are games that you play for your own money, they’re the ones that give you a chance to earn some actual cash.
Because you’re investing your own cash on these games you’ll need to manage your bankroll carefully, to make sure you don’t spend more than you can afford to.
It’s a great idea to set a limit before you play. That way you know exactly what your limits are and it's easier to stick to them.
Free slots
Credit: Mr Green Casino
Free slots are games you can play without spending any money, making them ideal for testing your skills before wagering your cash.
Many slot sites offer free versions of their real money slot games.
While each casino is different, you’ll often find the free version of the game advertised next to the real money one – there will generally be a button that says something like “play for free”.
Retro slots
Credit: bgo Casino
Retro slots are the classic games you’ll find at casinos.
You’ll be able to spot these slots because they are designed to look like the classic fruity machine games that are used in land casinos.
Retro slots also generally use three or five reels and one payline. This makes them simpler to play and means that they’re ideal for new players.
Video slots
Credit: The Sun Vegas Casino
Video slots are the most popular games you’ll find at most casinos, particularly ones that specialise in slots.
Video slots are incredibly varied, offering a range of reels and paylines, along with a broad range of themes.
Some of the themes you can expect to find include films and TV shows, games, and fantasy.
What are the best slot games providers?
Credit: Max Pixel
The best slot sites feature games from a huge range of providers, with some of these casinos using over 30 different software companies to supply their slots titles.
While there are many great providers, there are a few industry leaders you should look for.
3 top slot game providers
Playtech
Microgaming
NetEnt
We’ve assessed each of these great slots games providers in our casino software review.
It lists some of the top games made by each of these companies, so you can get some tips before you visit your favourite slot sites.
What is RTP & how does it work for slot games?
Credit: Flickr
It’s important to think about the payouts you're getting from the casino sites you bet at.
This is because it’s not a lot of fun if you don’t win the games you play and having fun should always be the priority when you’re playing the slots.
How do you measure the payout in slots? By the RTP (return to player). Here’s an example of how that works:
If a slot site has an RTP of 99.99%, this means that £99.99 of every £100 wagered is returned to players in the long run.
But, continuing with the example, what you need to know about RTP is that just because you spend £100 it doesn’t mean that you’ll get £99.99 back.
This is because the RTP of a slot site covers every player and every bet placed – and some bets win and some lose.
Key information about online slots bonuses and free spins
Credit: Wikipedia
Free spins are great for new gamblers who are deciding what slot sites they want to sign up to – they give you a chance to try out games without paying a penny.
While free spins might sound like a great deal (and in many ways they are) they do come with some conditions that you need to be aware of:
Free spins are generally for specific slots games
Free spins can be dished out in daily doses – not all at once
Free spins often have a time limit on them
And the thing to note is that free spins only apply to new gamblers. This means that if you’ve already signed up to a slots site you are no longer eligible to get its free spins offer.
Another thing to keep in mind is that many bonuses at online slot sites come with wagering requirements. This means you need to invest some of your own money to be able to withdraw the winnings you make from the bonus.
It’s not uncommon for bonuses to be subject to 35x wagering requirements, which means you need to wager 35 times the amount of the bonus to get the benefits of the reward.
It’s also standard practice for your free spins only to be available for specific slots titles, so you need to establish the funds count towards wagering requirements before playing your favourite games.
So, make sure you check the T&Cs of the offer before you sign up to make sure you know what the wagering requirements are before you place your bets.
How to have a great time playing tournaments at online
Online slot tournaments are a great alternative to traditional games. They’re a competitive way of playing online slots that offer some great prizes, with some tournaments giving you the chance to win a car or holiday.
The principle of slot tournaments is very simple. You enter a tournament and you’re challenged to play through a predetermined amount of slots as quickly as possible.
While the concept is straightforward this doesn’t mean slot tournaments are easy. They’re extremely competitive and the emphasis on playing at speed means you have to really think about each play you make.
In addition to having to make lightning quick decisions, slot tournaments also have a huge amount of variety to them. Some of the ways these tournaments vary include:
Games
Timeframe
Prizes
Spins
Alongside their competitive nature, speed and variety, one of the best things about online slot tournaments is they’re open to players of all types of bankroll — both small and large. This is because these tournaments use a percentage system to manage the gameplay, so all the players compete on an equal level.
If you’re looking for a testing alternative to traditional slots then try the Reel Thrill Slots Tournaments at Mr Green Casino. You can find out more about Reel Thrill Slots at Mr Green by heading to the site now and checking out its designated tournament games page.
Top slot sites for mobile gambling
Credit: Pexels
Mobile gambling is something that gamblers expect from slot sites – with more internet traffic coming via mobile than desktop, gambling websites need to have a mobile offering to be truly online.
Unsurprisingly, pretty much every slot site we compared has an app.
The apps created by slot sites replicate their website offering as closely as possible, with many being a mirror version of the site – for example, the number of games is often near-identical when comparing the app and website.
Credit: Pixabay
Because the mobile and online offering is so similar, this means the apps of slot sites must be judged on something different – how easy they are to use.
Many of the slot sites we reviewed have apps that are a breeze to use, honourable mentions going to:
LeoVegas
32Red
Mr Green
Betway
PlayOJO
Of these, one slot site stood out above the rest: PlayOJO Casino.
We think that PlayOJO Casino has the best app of all the slot sites we compared, but that’s not the only reason we think it’s great for gamblers – it also has some great roulette, poker, blackjack, and (of course) slot games.
You can learn about all the reasons we think it’s a top slot site by reading our full review of PlayOJO Casino.
3 top online slot sites for free spins
Slot Site | Free Spins Rating |
bgo | ⭐⭐⭐⭐⭐ |
LeoVegas | ⭐⭐⭐⭐ |
PlayOJO | ⭐⭐⭐⭐ |
Every slots site worth its salt will offer free spins and we found some great offers when comparing the very best sites.
However, there was a clear winner: bgo Casino.
Credit: bgo Casino
bGO Casino has a top free spins offer and you can find out exactly what it is by heading over to the site now. Be sure to check the terms and conditions of the offer before you sign up.
3 top online slot sites for free spins games
Slot Site | Games | OnlineCasinos.co.uk Rating |
PlayOJO | Over 2800 | ⭐⭐⭐⭐⭐ |
Mr Green | Over 1600 | ⭐⭐⭐⭐⭐ |
bgo | Over 1000 | ⭐⭐⭐⭐⭐ |
Games are one of the main reasons to head to a slot site – sure, you want to win some money but you need to place a bet on a game to do so.
Because there are so many slot titles out there, we think it’s crucial to compare how many games are offered by the leading slots sites.
And which site has the most? PlayOJO Casino, with an enormous 2800.
Credit: PlayOJO Casino
PlayOJO Casino’s huge games category puts it comfortably ahead of second-placed Mr Green.This means that it was a no-brainer to pick PlayOJO as being the best slot site for games.
3 top online slot sites for payout
Slot Site | Games | OnlineCasinos.co.uk Rating |
Mr Green | 99.90% | ⭐⭐⭐⭐⭐ |
Betway | 98.10% | ⭐⭐⭐⭐⭐ |
bgo | 98.00% | ⭐⭐⭐⭐⭐ |
First and foremost, playing slot games should be about one thing – having fun.
Slot games are like every other game, you play them to be entertained and your enjoyment should begin with simply participating.
However, like every other game, slot games do have an objective – to win. And the reward you get for winning slot games is money – your payout.
Payouts for slot games are measured in RTP and Mr Green is the site that offers the most attractive figure, with a high-end RTP of 99.90%.
Most popular slot games you can play
Credit: Wikimedia
Games are the key to the best slots sites. They’re the reason you visit them, the things that bring you fun from your gambling sessions, and the way you can win some cash.
The top websites offer hundreds, even thousands of titles that range from classic slots to progressive jackpot games, and this makes it tricky to know what the best ones are.
That’s why we’ve highlighted the five most popular slot games you can play.
Our 5 most popular slot games
Starburst
Leprechaun Hills
Centurion Free Spins
Game of Thrones
Casper’s Mystery Mirror
Starburst
Credit: YouTube
Payout: 96.10%
Paylines: 10
Jackpot: 250
Software provider: NetEnt
Leprechaun Hills
Credit: YouTube
Payout: 96.47%
Paylines: 40
Jackpot: 6
Software provider: Quickspin
Centurion Free Spins
Credit: YouTube
Payout: 95.00%
Paylines: 20
Jackpot: 500
Software provider: Inspired
Game of Thrones
Credit: YouTube
Payout: 94.86
Paylines: 243
Jackpot: 30
Software provider: Microgaming
Casper’s Mystery Mirror
Credit: YouTube
Payout: 95.50%
Paylines: 40
Jackpot: 500
Software provider: Blueprint Gaming
Gold medalist 🥇 PlayOJO: UK’s best slot site
Credit: PlayOJO Casino
OnlineCasinos.co.uk slot sites rating ⭐⭐⭐⭐⭐
PlayOJO Casino is number one when it comes to the UK’s best slot sites.
It has the most games, lowest wagering requirements for its bonuses, and one of the finest apps of any casino. It’s perfect for people who love to play the slots.
Top 3 features of PlayOJO Casino:
Close to 3,000 slots titles 🎰
No wagering requirements 💷
- Lots of jackpot games 🤑
Credit: PlayOJO Casino
Slots bonus package ⭐⭐⭐⭐
Vist PlayOJO Casino now to find out why it’s at the top of our list of the best slot sites and what its latest bonuses are.
Silver medalist 🥈Mr Green: huge collection of slots games
Credit: Mr Green Casino
OnlineCasinos.co.uk slot sites rating ⭐⭐⭐⭐⭐
Mr Green has an incredible selection of games that make it the envy of most slot sites.
It features a vast array of slots. Vegas slots, jackpots, instant wins, interactive titles, and retro options are among the many games that you can play.
Top 3 features of Mr Green Casino:
Diverse collection of slots games 🎰
Real Thrill slots bonus competitions 💷
- Great blog with helpful gaming tips 📚
Credit: Mr Green Casino
Slots bonus package ⭐⭐⭐
Head over to Mr Green Casino now to start using one of the best casino sites in the world and discover its latest bonus offering.
Bronze medalist 🥉 bgo: great free spins offer
Credit: bgo Casino
OnlineCasinos.co.uk slot sites rating ⭐⭐⭐⭐⭐
bgo Casino has one of the best free spins offers of all the slot sites we’ve reviewed.
It compares very favourably to the other online casinos we’ve reviewed. You can find out how it rates against other sites by visiting our casino reviews page. This page contains the latest bonus offers for all the best sites we’ve reviewed, including bgo.
Top 3 features of bgo Casino:
Daily slots tournaments 💷
Good selection of new slots games 🎰
- Weekly rewards hub 💸
Credit: bgo Casino
Slots bonus package ⭐⭐⭐⭐⭐
Check out bgo Casino now to learn what bonuses it currently has and see for yourself why it’s one of the best UK slot sites.
LeoVegas: combination of great payouts & lots of games
Credit: LeoVegas
None of the other slot sites we’ve assed match LeoVegas Casino for the combination of games and the level of payout offered to gamblers.
It features over 600 games and has an RTP of 97.60%, making it not only a fun website but one where you could earn some cash.
This means that LeoVegas is the best option for casual betters who play for fun and more serious gamblers who want to win some money.
Visit LeoVegas now to discover the casino’s bonus package and play its many great games.
Grand Ivy: excellent variety of video slots
Credit: The Grand Ivy Casino
If video slots are what you look for in your slot sites then Grand Ivy Casino is perfect.
Grand Ivy Casino has a superb range of games and its site makes it easy for you to find the ones you want. It does this by letting you filter by the software provider (such as Play n Go) or name of the game.
So, if you’re a fan of video slots then pay a visit to The Grand Ivy Casino today.
888: trustworthy slot site
Credit: 888 Casino
888 Casino is a slot site that’s reliable, trustworthy, and safe.
You can be sure you’re safe when you play slots at 888 Casino because it was voted the Best Casino Operator at the 2020 Gaming Intelligence Awards and 2019 EGR Awards London.
These are awards that only truly secure casinos can win.
Try the 888 Casino website now to see with your own eyes just how trustworthy it is.