Best Online Slots Sites in the UK

Top Slot Games for UK Players

Online slots have seen huge growth in the past decade. The number of games has increased dramatically, as well as the quality and the features incorporated in what used to be 'dull' three-reel one-arm bandits.

It can be difficult to find the best slot sites and understand what slot machine games are worth playing - especially if you are new to the genre and you are not familiar with game developer names and concepts like RTP and volatility.

The oddschecker Casino team has created what we believe is the best guide to online slot machines for players in the United Kingdom.

Here you find everything you need to understand how to pick the best slots to play online as well as the most lucrative bonuses and free spins available on the best slots sites.

We show you how the different slot games work and what aspects make them a good or a poor choice for your real money games. This way, you can make informed decisions and always pick the top UK slots to play.

This article focuses on the top UK online slots sites in 2021.As you are about to find out, here on oddschecker, we take great pride in testing all the gaming operators approved by the UK Gambling Commission so our readers can access the best games on the top brands out there.

Continue reading the oddschecker guide to casino slots online to learn:

• How do online slots work
• How do we pick the best slot games to play online
• What is the Return to Player and why you should care about it
• What casino slots you need to try when you play online
• How to get the most out of free spins and demo games
• What sites offer the Starburst™ XXXtreme slot machine
• And a lot more

We tried also to answer all the most popular questions about wagering requirements, casino bonus offers, and many more aspects that are relevant to every player looking for info about real money slot machine games.

In other words, if you are looking for a way to discover the world of online slots and find out what are the best slot sites to get some bonus money for your games - you'll love this guide!

How to Play Online Slots in the UK

Judging by the sheer amount of slot sites out there and the impressive number of games they feature - it would seem like all casino players spend time playing online slots.

Technology sure helped the diffusion of these gambling games. Online play allows players to log in and begin playing whenever they want. Although this might 'de-humanise' gambling and remove the fun that comes with the traditional brick-and-mortar casino experience, some players believe online play offers a better experience overall.

Mobile slot games have allowed players to access the games from their smartphones and tablets, removing also the need to be at a desktop computer to fire up a slot and play.

While we will discuss mobile gaming later in this guide, it is clear that the growth of the mobile arm of the best slots sites for UK players has influenced the popularity of these games.

Before we discuss the complexity of online slots and the different type of games you will find on the different slot sites available in the UK, it's worth noting also that the Return To Player (RTP) percentages tend to be higher online than at most casinos.

While this does not mean that you are guaranteed to win when you play online, higher RTP percentages mean that players get a better deal.

The slot sites in the list above feature games with an RTP between 93 and 98% - which is generally higher than what you find at most live casinos.

Online slot sites make it easier for you to pick the slots with the highest return to player as they implement filters that help you do just that. And when they don't, you only need to follow our slots tips to pick the best slot machines to play -- every time.

How Do Online Slots Work

Online slots are among the simplest casino games to understand. That doesn’t mean they’re unsophisticated or boring, far from it. Their fundamental mechanics are easy to master, particularly when compared to the vast majority of table games you find on all the top UK online casinos.

Unless you run into a special bonus game or you begin the (often endless) chase of a progressive jackpot, all slots work in the same way. You:

1. Set your desired bet
2. Hit the spin button
3. Wait until the reels stop spinning and show the result of your game

This basic gameplay changes in some of the newest video slots where bonus games and other features add a few layers of complexity that might require you, the player, to take in-game decisions that can affect the end result.

Slot machines are based on luck. While your choices can influence your chances to win (wait to hear about different payout slots and the return to player percentage), there are no strategies that can guarantee you a chance to win.

Online Slots Betting Tips

Depending on the slot machine you pick, sizing your bet might include a few variables you should be aware of. These influence the cost of your spin and, should you come out a winner, the sum you can put in your pocket, too.

Each slot has its own betting limits, but it’s typically the case that minimum bets start at £0.10 per game or £0.01 per payline. In certain slots games, you’ll be able to adjust the number of active paylines and the number of coins (i.e. bets) you want to invest on each payline.

The more variables you can adjust, the more control over your bet size you’ll have -- and that's clearly a good thing. What is not so good about these casino games, is that the only way to access the top wins on a slot game with said betting options is to play all paylines and invest the maximum amount of coins allowed. In other words, these games are expensive and might not be a good fit for everyone's bankroll.

This is specifically the case of jackpot games. The most popular casino games at brick-and-mortar casinos are also the most expensive and elusive gambling games part of the slots family. Taking down the top prize on a slot game with a progressive jackpot requires slot players to commit to playing the maximum bet every time - meaning one could easily run out of funds in just a few rounds.

So - you might be thinking: " how much money do I need to play slots online?"

Although every player might have a different answer based on their disposable income and the reason they play casino games online, here are a few slots tips that will help you understand how to size your bets correctly.

1. Play to have fun, not to get rich. Every online slot game you find is based on luck, so the outcome of every spin is completely out of your control. Knowing this, it should be clear that you should fire up a slot machine to have fun while you play -- not to chase results that, again, do not depend on your actions.
2. Play money you can lose. It doesn't matter what slot titles you play or whether you picked a high-volatility slot with a high RTP or not: always play casino games with the money you are not afraid to lose. This will help you define the size of your bankroll and understand how much you can invest in online slot games.
3. Decide how long you will play. Once you know how much money you can spend to have fun playing on slots sites, decide how much time you are going to dedicate to the games. If you plan to play for hours on, you'll need a big bankroll and you'll have to settle for £0.10 games and penny slots. If you are in for a quick bite, who knows, perhaps your bankroll could even fit some jackpot games!

Once you’ve found the sweet spot, hit the spin button and wait. Finding the ideal bet size takes a bit of work - but it's really all there is. Anything after that is in the lap of the slot gods. The reels spin and, if you match enough symbols across an active payline, you’ll be a winner and take home a prize.

Types of Online Slots

The variety of slot games that are available today is one of the main drivers of the popularity of this genre. There are many types of slot games, so it is important to understand which ones you should be looking out for and which ones will best suit your needs.

The following list covers the main games you’ll find at our recommended casinos and some the top titles within each.

Classic Slots

These games are digital replicas of one-arm bandits and fruit machines that made the fortune of Las Vegas and Atlantic City casinos. Most of these titles feature three reels and 1-5 paylines. Add to this a collection of familiar symbols, such as fruit, bells, and 7s, and you’ve got online games that hark back to a time before the internet.

Depending on the slots sites you pick, these games might be categorized also as Vegas slots or fruit slots - so you better keep an eye out for these specific themes the next time you register to play on a slot site.

When it comes to the best classic slots to play online, these are the top 10 titles that UK players love:

Video Slots

Video slots form the backbone of almost every online casino and, let's face it: these are the games most players enjoy. Numbers can vary but it’s not uncommon to see 500+ games packed into a single slots site. Some of these games can feature three reels but it’s much more common to see five...or more!

The number of paylines can be anything from 5 to 100+ and there will often be at least one bonus feature. In fact, it’s bonus features that help define video slots and make them popular. The other major selling point is the “video” element.

Animations and in-game video clips add another layer of entertainment to the overall experience.

The top 10 video slots in the UK in 2021 include a mix of classics like Gonzo’s Quest and Starburst sitting alongside a number of interesting new games.

Branded Slots

The branded-slot category includes some of the best-known gambling games available online - with titles that are popular also among the players who have never played them.

Branded games are associated with movies, TV shows and sports teams, as well as popular brands of other fields and industries.

The fact these games act as the official 'ambassadors' of popular brands in the gambling world pushes developers and game studios to go the extra mile and bring to the market (and the slots sites) titles with top graphics and gameplay.

While these are often not the highest-payout slots on offer at most UK slot sites, the gameplay and features of these real money games more than make up for that.

Seasoned casino players will know most branded slots from their trips to the gaming floor at brick-and-mortar casinos. If you are not such an experienced player, these are the top 10 branded slots to play online in 2021.

Progressive Jackpot Slots

Jackpot slots are considered royalty in the online gaming world because they offer the richest payouts. These larger-than-average prizes are created through a system of communal contributions. A small percentage of each bet you make goes into a communal prize pool. The same goes for everyone else playing the jackpot slot in question.

Because there are thousands of players adding to the pot every day, the top prize is always increasing in value. Moreover, the value of said jackpots far exceeds anything non-progressive games can offer. This means prizes worth more than £1 million are common.

As we said earlier, these slot machines are not for every player. Jackpot slots can be very expensive - especially as the only way to play for the progressive jackpot is to bet the maximum on every spin. When it comes to jackpot slots, our advice is not to get too fixated on the seven-digit jackpots advertised by the different sites, but continue to play for fun.

If you are interested in jackpot slots and you would like to know more about the top jackpots in the UK as well as the real chances you have to take down one of the top real money prizes up for grabs, we have an in-depth guide dedicated to the best progressive jackpot slots to play online.

As of 2021, the most popular slots with progressive jackpots in the UK are ones grouped in the table below.

Megaways Slots

Modern technology has transformed slots in recent years. One of the latest innovations to strike a chord with players across the UK and beyond is Megaways. Dreamed up by Big Time Gaming, this technology creates a random payline structure.

The premise is thus: the number of paylines changes each time hit the spin button. There are usually six reels in play and the number of active paylines can range from a few hundred to 117,649.

In fact, some of the more recent Megaways slots have over 200,000 paylines. This level of potential is obviously appealing. However, the main reason more players are spinning these slots is that you never know what’s going to happen next. One minute you’ll have 500 ways to win, the next you’ll have 5,000. That’s entertaining.

Some of the best Megaways slots online available to players in the United Kingdom are:

How to Pick the Best Slots

Before we answer that and we try to come up with tips to pick the best slot machines every time you play, it’s important to note that “best” is a relative term when it comes to anything that has to do with online casinos and real money gambling.

No one can point to an objective reason as to why X is better than Y. Some players like classic slots with three reels, others prefer Megaways games with 117,649 paylines. Therefore, any list we produce will always have an element of subjectivity. But what we also try to do is look at the facts and give you a list of games highlighting key slot features like the RTP, the volatility, and the payout percentage.

We want you to use our guide as a starting point. Use it to learn more about how to pick the right slots for your money, what slot providers to consider, what features matter most, and how some forms of gameplay impact your chances to win.

From there, you can compare these qualities to other slots and find one that suits your preferences. Finding the best slots online is part scientific inquiry, part art. With that in mind, here are five features that all of the top online slot machines have in common.

Return to Player

The Return to Player (RTP) is expressed in percentage terms and it indicates how much of the wagered money a slot machine will pay back to players over time.

While it is always good to pick a slot machine with a high RTP, this should not be considered as a guarantee that players will win -- as the RTP is a theoretical number calculated 'in the long term,' or taking into consideration an undefined large number of gaming sessions.

The flip side of the Return to Player is the house advantage, the mathematical edge online casinos have over the players, and the reason why we continue to stress that gambling is a matter of luck and real money games should be played for fun and not to seek any financial profits.

Following the rules imposed by the UK Gambling Commission, all the online casinos the operate in the UK need to publish the RTP of all their games. On nearly every slot site out there, you find this information by clicking on the 'i' button included in every slot machine game.

Volatility

The concept of volatility (often referred to also as 'variance') is an important one when it comes to defining the payout percentages in slot games.

Volatility refers to both the frequency with which a slot pays out and the size of the prizes it pays out. When it comes to volatility on slots, there are three types of games to consider:

• Low-Volatility Games: these are the slot that pay out often, but where the winnings are very small in size.
• Medium-Volatility Games: these offer frequent wins and in different sizes.
• High Volatility Slots: these are the slot with the biggest payouts. Unfortunately, these are also the games that do not distribute big wins very often.

While online casinos are obliged to share the RTP and house advantage of their games, they do not need to show details about the volatility.

The best way to know what cluster a slot game belongs to is to read slot reviews or use free spins to understand how the game behaves.

Some of the best-known low-volatility games include the penny slots part of the Quick Hit series by Bally. When it comes to high-volatility ones, the most famous game of this kind is Microgaming's Mega Moolah.

Broad Betting Limits

The best online slots are accessible to everyone. Although demo slots allow you to use virtual chips and play for free, playing these casino games for real money should never cost more than you are willing to spend. You have to make real-money bets if you want to win cash prizes and there needs to be betting limits that suit all players. The best slots have these.

As a general guide, we like games that allow 1p coin size bet and that do not require too much money to enjoy a few good spins.

Varying Variables

Many slots don’t allow you to adjust anything other than the size of your bet between spins. However, there are some that allow you to adjust the number of active paylines and the amount you’re betting per payline. Having the ability to adjust these variables isn’t a necessity but it is nice to see. The more things you can tweak, the more control you’ll have over the amount you’re betting and the actual cost of all your spins.

Special Features, Bonuses, and Other Extras

An online slot becomes a hot slot when it’s packed with extras and features more than just one bonus game. Spinning symbols is great but we all love when spins trigger unexpected surprises. This is where mystery pick’em bonus rounds, wilds, free spins, and multipliers come in.

Each of these extras adds something to the base game and, in turn, give you more ways to win or to enjoy the time you spend playing slots. What’s more, they give slot providers a chance to indulge their creative sides and build a narrative into their games. This combination of storylines and random surprises is entertaining and the reason many slots stand out from the crowd.

Entertainment and Engagement

The final quality that all the most popular online slots share is entertainment. Although the themes and underlying storylines will be different, all the hits encourage a certain amount of engagement. This could be through some atmospheric sound effects, in-game videos, or interactive bonus rounds. If you’re playing the best mobile slots, you can also use things such as swipe-to-play and shake-to-play. These features make your experience even more tactical and, therefore, immersive.

Best Online Slots for UK Players in 2021

By now, you should know how to browse through the games offered by all the top online casinos to find slots with the right betting options, RTP, and volatility for you. And even if it's fair to say that the best slot games online are those you enjoy the most, there are a few games that have all the right numbers to be at the top of every player's list.

That's why we prepared a list of the 15 best slots in 2021 that UK players can enjoy with free spins and bonuses. Check out the list of the most popular slots in 2021 and visit the best online casino for each game to discover what bonus offer you can claim.

What Online Slots Pay Out the Most?

It's essential that you understand the payout percentages for real-money slots if you are one of the many people who enjoy playing online casino games. This part of our guide to the best games and slot sites will cover all the most important aspects of online and offline casino payout percentages. With this information, you will be able to understand how to find the best slots, as well as what slots site to pick when you want to play.

The most experienced players always seek out the slots with the highest odds of winning. While it is fine to gamble for entertainment, you should also know that you will have more fun if you have the best odds of winning.

This section will explain how to choose the best games, and how to maximize your chances of winning when you play slots. If you want to jump in the action immediately, check out the table below to find some of the slots that pay out the most at online casinos available in the United Kingdom.

Online Slots with the Best Payout

Before you deposit money and invest real cash on the best slot sites, always check the pay table of the game you are about to play. The pay table is where you see all the most important details of the slot, including the maximum payout possible, the RTP, and the combinations that lead to the biggest wins.

Always verify the type of slot machine that you are playing. While Vegas slots may sometimes offer the same payouts as progressive games, you should not expect to win a jackpot playing penny slots machines will be disappointed.

Also, when it comes to the RTP, make sure to play the game that offers a percentage of at least 90%. These games are more likely to pay out than those with lower RTPs.

When it comes to the slots with the best payouts, these are the games available at the best slot sites in the UK:

How to Find Loose Slot Machines

Online casinos are your best option if you want to find and play loose slots online. Lower operational costs mean that online casinos can offer games with higher RTPs compares to their live counterparts and, as you now know, this is a good thing for players.

Players refer to slot machines' payout percentages when they call them "loose" or "tight". A looser slot machine pays out more frequently and at a higher percentage, while a tighter one pays out less often and has a lower RTP.

The "hit frequency" stat is another important stat you should be looking for. This percentage also refers to the likelihood that each spin will result in a win for the player.

This number doesn't indicate how much the player wins. It simply indicates how frequently the player will win more money than losing. One in five winning combinations will be generated by a game that has a 20% hit rate.

If you want to play loose slots, look at the RTP and use the internet to read slot reviews. The best choice is always to use your spins on slots with a high RTP percentage. So, do your research and aim at titles that come with a house advantage of 5% or less.

Top Slot Game Providers

All the tables on this article include a column dedicated to game providers, the companies that produce the games you see listed on the casino sites.

Most gaming sites do not develop their own games, they 'rent' them from other companies. This allows them to tap into the talent of skilled game developers and add hundreds (when not thousands) of different options to their portfolios.

Since not all game studios are created equal, this part of our guide gives you an overview of the top names in the industry.

NetEnt

Headquartered in Stockholm, Sweden, but with offices in numerous different countries, NetEnt is a true leader in the world of modern video and 3D slots.

NetEnt games stand out for their modern and vibrant graphics as well as for their engaging gameplay.

The list of the most popular games ever produced by NetEnt includes modern classics like Starburst, Gonzo's Quest, and Narcos. For a complete overview of the top titles by this developer, don't miss our list of the best free NetEnt slots online.

Microgaming

Microgaming has the largest number of games and casinos that use its products. This brand is one of the few companies in the gambling world that can act as a standalone developer of casino software.

If you have reached this part of our guide, you'll know that Microgaming is one of the top providers of jackpot games, especially thanks to their record-shattering Mega Moolah. Microgaming is very active also in the world of branded games, as the company inked strategic deals to create games like Hitman, Game of Thrones, and Jurassic Park.

Last, but not least, the creative minds at Microgaming are also responsible for series like Immortal Romance and Thunderstruck, as well as Avalon.

Playtech

Playtech is another big player in the world of all things gambling. Active since 1999, Playtech was one of the first developers to specialize in casino games and one of those who contributed the most to the explosion of online gambling in the past decade.

Playtech, like Microgaming, is one of the few brands in the industry to have enough games and software options to power entire casinos by itself

With such an extensive range of slots to Playtech's name, it's hard to point at their most popular titles. Looking at the world rankings, however, it would appear that the list of most popular real money slots by Playtech includes the likes of Justice League, The Dark Knight, and Frankie Dettori’s Magic Seven.

IGT

Over the past decade, IGT has been able to focus on themed games as well as branded slot machines. They split their efforts between live and online casinos to create a large number of slot machines you can find in casinos around the globe.

There are a lot of online slots in the IGT gaming portfolio. The best thing about the way this company works is the fact that games that are outdated or not up to standard are either refurbished or removed. Although this is uncommon, it is a great user experience.

Here are some of the most popular games released by IGT: Family Guy, Ghostbuster Baywatch, Cleopatra, and Wheel of Fortune.

Play'n Go

Founded in 2007, Play'N Go is another popular Scandinavian brand busy with developing some of the best slots available to casino players today.

Troll Hunters 2, Rich Wilde, the Shield of Athena, and Rally 4 Riches are just a few of the outstanding games created by the brand. Each of these games has a unique storyline and gameplay that unfolds as you play, revealing free bonus rounds as well as features that are not available on titles produced by other brands.

Yggdrasil Gaming

Yggdrasil Gaming is one of the most recent (and biggest) success stories in the game software industry. Although the company was founded only in 2013, they have managed to establish themselves as one the most respected in the gambling vertical.

Yggrdrasil is known to be the name behind some of the top-quality slots in the market today. Three of their most popular titles and three slots that are perfect to understand what makes Yggdrasil so special are Vikings Go Wild and Vikings Go Berserk, and Blood Moon Wilds.

Novomatic

In the business since 1980, Novomatic is one of the most recognized creators of casino games for brick-and-mortar casinos. To date, their products continue to attract players -- especially since over 2,000 casinos in the UK alone offer them!

Novomatic offers a wide range of online slot machines, as well as over 2,000 casinos in the UK that host their games.

Their most well-known game is the Book of Ra, but they also offer other games like Lord of the Ocean and Dolphin's Perl.

Casino Bonus Offers and Free Spins

Online casinos are known for their welcome bonuses. We can be honest and say that many casinos these days are very similar to each other due to different platforms sharing the same games created by the providers we just mentioned.

One thing that makes casinos different, however, is their bonus offers. Every UK gaming site offers a casino bonus. Some sites bet everything on free spins offers (pun intended) while others try to differentiate themselves from the rest with no deposit casino bonuses.

Bonus offers to play slots come also with different terms and conditions and different wagering requirements that apply to your bonus wins.

It is important to remember that casino bonuses are rarely free money. For example, a welcome bonus is money that the casino gives out to new players. However, in order to withdraw the cash you must meet certain criteria regarding your gameplay and bet the entire amount of the bonus a set amount of times. These are also known as wagering requirements.

After you receive the bonus, you will be asked to wager the bonus at least once before you can withdraw the money. In the United Kingdom, the wagering requirement can vary from 20x to 50x the bonus amount.

Occasionally, some casinos give away free spins with no wagering requirements. These offers are difficult to find as slot sites tend to save them for special games and occasions. When available, no wagering free spins offers tend to be out for a limited amount of time and to be connected to specific games and payment methods. You can find the latest offers of this kind on our page dedicated to free spins offers for existing players.

You should also be aware of the time it takes to clear your bonus. Also, you need to know what games you can play in order to clear your bonus. What deposit methods are eligible for you to claim the bonus, and so on.

Free spins can be a bit more complicated than other bonuses for slots. You will receive bonus spins on certain slots, and any winnings from these you can usually keep.

Other limitations that usually apply to free spins offers include the maximum stake per spin and the number of spins permitted. You also have restrictions on the games you can use your free spins for.

How to Play the Best Slots for Free

You can play the best slots online for free in two ways. The first is demo slots, which you can read about here. The second way is through free spins slot bonuses.

Free Play Demo Slots

Demo slots are free-to-play versions of their real-money counterparts. They offer full functionality without the cost. For example, you can play the demo version of Starburst and toggle the bet size, spin five reels and try to match celestial symbols in pursuit of prizes worth 500X.

The only difference between the demo version of Starburst and the real-money version is that you’re betting with virtual chips. Anything you win will be paid out in virtual chips that don’t have any real-world value.

Free spins online slots bonuses

Another way to play the top slots for free is through bonuses. Our partner casinos offer everything from free spins to free credits. You can use slot bonuses to play an array of games without spending your own money.

What’s crucial here is that you’ll have the chance to win cash prizes. There may be certain post-win wagering requirements. However, the main point to note here is that you can use bonuses to play slots for free and win some money. If you want a complete overview of all the promotions available in the UK, check out our list of no deposit free spins offers.

FAQ

Is there a best time to play slots?

No. Unless you decide to play live slots, choosing a specific time will not affect the result of your games in any way. Contrary to popular belief, slot machines do not pay out differently at different times of the day.

How to know if a slot machine is about to pay?

In theory, knowing a game's variance, a player could predict when a slot is about to pay by calculating the number of spins it did not pay out any prizes. This, however, is impossible with modern slot machines and video slots - as the variance is calculated over an undefined number of games.

Also, the result of the spins is controlled by a Random Number Generator (RNG), a sophisticated algorithm created to make it impossible for players to know when a slot is about to pay.

How to pick a winning slot machine?

Your best chance to pick a winning slot machine is to choose one of the games with high RTP listed on this guide. While this system does not provide any guaranteed wins, it does give players their best chances to win money on slots.

Keep in mind that slots are a luck-based gambling game where the casino has always an advantage over the players. By picking the slots with the highest RTP, you only reduce the house edge.

Are online slots safe?

Yes, all online slot games, including the best ones, are completely safe. We only recommend online casinos that are licensed and regulated. That means the games within these sites are tested and certified as safe and fair. These tests are carried out by third-party agencies such as eCOGRA so there’s no tampering with the results. Therefore, if you use one of our sites, you can play the best slots confident in the knowledge they’re 100% fair and safe.

Can I play the best online slots for free?

Yes, you can. If you’re happy to play for fun and don’t mind the fact you can’t win cash prizes, demo slots are ideal. These games offer full functionality without the cost. If you want to play for free but win cash prizes, you can use online slot bonuses.

Where can I find the best slots online

The best online slot machines are housed inside our recommended casinos. Using our secure registration links, you can access sites such as BGO and Energy Casino and play all the top slots, including Starburst, Gonzo’s Quest, and more.

Who makes the top online slots?

The best online slots are made by NetEnt, Microgaming, Playtech, Yggdrasil, and others. In fact, there are almost too many developers to mention. The slots market has become so competitive in recent years that everyone has raised their game. This means you can find world-class products from almost every developer. What’s more, you’ll be able to play the best slots on mobile and desktop devices.

Check out our top-rated casinos, create an account and start playing the best online slots today!

Need More? Don't Miss These Pages!

• £10 No Deposit Slot Bonus UK
• List of the Best New Slots
• Live Slots
• Best Mobile Casinos
• All Casino Reviews