Playing Online Slots – All You Need to Know

On this page, we will look at some of the best online slots for UK players, the different types you can play, and what options you have online.

There are now over 20,000 online slots  that you can play on your PCs, smartphones, or tablet. We will help you find some of the most popular, and look at what are the most important things to know when playing.

Topics we will cover:

• The different types of online slots.
• The 3 Best Online Slots Ever
• How online slot games work.
• Options to play slots with money or free online.
• Online and live casinos slot development and crossovers.
• Various regulatory issues that come along with online slots.
• Who can play online slots and the amount of randomness in online slot games.

Various Types of Online Slots

Lets look at the most popular types of online slots

• Video Slots – mostly have 5 or more reels, they have advanced graphics, can come with animations, different features, and most offer free spins or bonus games.
• Progressive Slots – are also video slots, but they have one or more jackpots that increases every time the game is played. Some jackpots can reach £20 million or more.
• Megaways Slots – are relatively new and popular slot type with dynamic reels that change the number of symbols per spin. They usually offer 243 up to 117,649 ways to win each spin, but they can go up to millions of ways. For example, Rasputin Megaways has 2,985,984 ways to win.
• 3D Slots – are slots with three-dimensional graphics
• Classic Slots –  traditional three-reel slots, often with simple symbols like fruits and bars, the popularity of these slots has gone down over the years

3 Candidates for The Best Online Slots Ever:

One of the most common question we get is what is the best video slots ever made. Below you will find three strong candidates for that title:

1. Gates of Olympus 1000 – is one of the most popular online slots ever made. It actually comes in 2 version Gates of Olympus and Gates of Olympus 1000.

Gates of Olympus 1000

2. Pirots 3 – is a masterpiece in features and fun game play. This is the 3rd game in the Pirots series from slot provider Elk Studios. The game has become very popular at UK online casinos.

Pirots 3

3. Le Bandit from from Hacksaw is new popular slot with fun game play and four buy feature options.

Le Bandit Slot Screenshot

Browse our highest-rated slots collection

How Online Slot Games Work

Each time you play an online slot, a computer program called a Random Number Generator (RNG) decides the outcome. As soon as you hit ‘spin’, the RNG picks a random number for each reel, which corresponds to a spot on the reel. The spot where the reel stops is called a “stop”.

Each stop represents a symbol on the reel and this combination of symbols determines whether you win or lose. The odds and payouts are set according to the game’s ‘paytable’, which lists the winning combinations of symbols and the amount of payout for each combination.

The diversity of online slots means each game can have unique themes, symbols, features, and bonus games, but the underlying technology of the RNG remains consistent. This ensures fairness and randomness in all games, so every player has an equal chance of winning with each spin. The thrill of online slots is in the unpredictability and the chance of hitting a big jackpot/good bonus round at any moment!

The Bonus Feature/Free Spins – The Highlight of The Game

Online slot games often have a bonus feature often known as Free Spins. This feature is usually triggered when you land a certain number of special symbols, like scatters, on the reels. Once activated, you get to spin the reels for free for a set number of times.

During these free spins, you might encounter multipliers, special wild symbols, or other bonuses that can significantly increase your winnings. The exact nature of the free spins and how they work can vary from game to game, adding an exciting layer of variety and anticipation to the gameplay. It’s always a thrill to hit this feature because it means a chance at bigger wins without betting more of your own money.

Land-based slots vs Online 

Online slots are basically a variation of the popular video slots found on land-based casino floors today. Because of that, there are quite a few similarities between land-based casino slots and online slot games. The following are some of those similarities that are easily noticed between the two types of slot games:

• The winning results when it comes to online slots are determined by an RNG (Random Number Generator), which is similar to the slot machines in land-based casinos.
• Almost all online slots allow multiple paylines, with most of them featuring five video reels, which is similar to the slot machine games in land-based casinos.
• There is also a small amount of slot games online that feature three reels. Some of these three-reel slot games also mimic the mechanical reel slot machines that are found in casinos.
• When it comes to online slots, the bonus game/free spins bonus account for a large percentage of the payback, which is another factor that is similar to the live video slots found at land-based casinos. 

Nowadays, it is easy for slot enthusiasts to find their favorite games both offline and online from big-name manufacturers such as IGT, Aristocrat Technologies, and Williams Interactive, a division of Scientific Games.

These famous slot developers offer online versions of many of their popular casino slot machines. This allows players to enjoy their favorite games from home without traveling to a physical casino.

High Five Games is an independent slot game design company that has been particularly active in the design and development of online slots. High Five Games has also sold their slot games to other well-known slot manufacturers such as Bally, WMS and IGT. The slot games that High Five Games have designed features double symbols, as in, two of the same symbols in a single space, making it possible for users to play with ten of a kind symbol combination, which was never done before with online slots.

Besides having many things in common, there are some areas where online slots differ from the land-based casino slot format. The following are some of the differences between online and land-based slots:

• Online slot games offer many wagering options, and often more features.
• Unlike land-based slots where a user has to pay to play, those who play online slots can first try out a slot machine free without having to make a real money wager.
• Payout percentage(RTP) is higher on online slots compared to land-based slots, land-based slots have an real time payout (RTP) around 89% to 93.5%, where online casinos slots approximately (RTP) are 91% to 98%.
• When playing at Land-based you can have social interaction and talk to other that are also playing, that is not possible online.

Bonus Wheels and Progressive Jackpots

Bonus Wheels

When it comes to land-based casinos, the slots featuring bonus wheels are a permanent staple for drawing in large crowds. The bonus wheel games usually tower above all the other base games that are on the casino floor since these slots are also visually appealing and help attract the most players. But, when it comes to online slots games, you don’t have to compete with other slots and casino games for the attention of the players. This makes the use of wheel games unnecessary. On the other hand, when it comes to the progressive slots, the bonus events do not rely on bonus wheels, but rather on pick ’em bonuses and free spins to draw in more players.

Progressive Slots

There are many brick and mortar casinos in the UK, USA, and the world where up to one-third of the slots are progressive games. This is true for those slot games in live casinos that use multi-level jackpots, bright lights, and loud sounds to draw players towards them whenever they are free. These slot games mainly cater to jackpot hunters in land-based casinos. While such slot games are also available in the online format, the proportion of the progressive games is lower in online casinos than in land-based casinos.

Options to Play Slots with Money or Free Online

Many slot games at land-based casinos are tied to specific coin denominations, such as the 1-cent slot machine. As the name implies, players are only able to wager up to 1 cent per payline, or 25-cent machines, or $/£1 slot machines. Even in those slot machine games in land-based casinos that do offer multiple denominations, the players usually find themselves with a limited number of options. The most common denominations that slot players have to choose from are 1, 2, 5, 25, 50, and £1 per payline.

Keeping that in mind, online slot games are considered to be far more flexible. In online slot games, players can make all the potential wagers per line along with other amounts if they have the available credits.

Online players can also play the games in free version.

The best part about playing online slots in full-play casinos or social casinos is that players have the option of playing for free. Unlike land-based casino slots where the players have no choice but to make a wager whenever they play the slots, in online slot games, the player gets to choose whether they would like a particular slot game by trying it out with the no-wager option. This Feature has drawn millions of slot enthusiasts towards the online format. Of course, those who play for free cannot collect any prizes. You have to play for real money to be able to win real money on online slots, and therefor developers have designed slot games where the players get the option to make wagers for real money.

Online Options

When it comes to slot games that are available in the online format, there are often thousands that one can play in an online casino. The reason the casinos have so many different online slots is that there are now so many game providers, the casinos can choose from . That way, every online casino does not have the exact same selection of slots see them all here. 

The multitude of slot games available in the online format makes it easier for just about anyone to find the right slot game to play in the comfort of their home or while on the go.

Lets look at some of the games with the highest RTP:

Quick Facts:

• In a way, the online slot game format is an extension of the popular video slots in casinos that have now been made available in an online environment.
• Online slot games use many of the same methods of attraction as the live video slots such as the Pick ’em bonuses and Free Spin bonuses.
• Many of the famous slot games that are given in the online format have their live casino counterparts, along with having their own proprietary games as well.

Randomness in Online Slot Games

While both land based slot games and slot games available on online casinos may look similar online casinos do have their own set of terms and conditions which are imposed by the jurisdiction in which the casinos operate. The following are some of the quick facts one should consider when using online slot games.

Quick Facts:

• Who is allowed to play?
• On which devices can users play?
• How many online slot players deposit?
• Are the slot games offered online similar to those offered in live casinos?

Who is Allowed to Play Online Slot Games?

What makes online casinos so attractive to many slot enthusiasts is that online casinos contain dozens of slot games from which to choose from. Online casinos contact various slot developers who then provide their games. What follows is a selection process of the slot games that the online casino wants to use. The growing popularity of online casinos means that online slots are legal in most countries, with a few exceptions.

That being said, the online casinos govern their own rules and regulations as to who is allowed to play, which is mostly following the regulations of the host country in which they operate. For instance, in the United Kingdom, there is a Gambling Commission whose job it is to regulate online casinos along with sports betting, racing, bingo, land-based, live casinos, and arcade games.

Keeping that in mind, one of the most important feature of any online casino is geo-location, or the online casino’s ability to track the location of their players. The online casinos can accept wagers from players in multiple countries where their online casino is legal, which is the case in the UK, but not the case in the United States, where slot wagering online is not considered to be legal in many states. This means that slot players in the US aren’t only restricted from using online casinos in their own states. They are restricted from using online casinos from other states or countries as well, with the only exceptions being Delaware, Nevada, and New Jersey.

In 2014 in the USA, the states of Nevada and Delaware agreed to a compact that allows poker players to participate in each other’s online casinos. The online casino industry remains optimistic, as more states are legalizing or considering the legalization of online casinos

When it comes to where online casinos can be played, it is up to the jurisdiction of each of the states which have their own regulations and licensing terms. Online casinos that operate in New Jersey are required to be affiliated with the state’s live casinos before they can offer their games online.

In Atlantic City, the casinos have forged an alliance with those companies who already have expertise in online casinos. Caesars Interactive Entertainment is associated with Bally’s and Harrah’s casinos located in Atlantic City forged alliances with 888 Casino for the development of online games. Also, in Atlantic City, Borgata, Resorts, Tropicana, and Golden Nugget all formed their own alliances with other companies to develop their versions of online casinos.

Whether other US states adopt new restrictions on where the users can play in still unknown, players who want to use online casinos in other states will have to wait and see for the legalization in those states where playing on online casinos is not yet allowed.

New Types of Online Slots

Man, the slot world has changed a lot. A few years back, everything was just the basic three-reel machines — spin, stop, maybe a line or two. Nothing fancy. Now it seems every time I log in, there’s some new type of slot I’ve never seen before. It’s wild.

I’ve been playing for around 15 years, and I swear, the difference between then and now is night and day. Back then it was literally, pull the lever and just hope something lined up. That was it. No thinking, no features, nothing. Now you’ve got bonus rounds inside bonus rounds, reels that zig-zag all over the place, and mini-games popping up out of nowhere. Half the time I forget I’m even playing a slot — it’s more like some weird mash-up of a game and a slot machine. The new stuff barely even feels like the old-school slots we started with.

Here are some of the newest slot styles showing up at UK casinos — and a few of them are real game changers.

Progressive Sweep Slots

These are a newer twist on progressives. They mix the thrill of chasing a growing jackpot with the mechanics of a sweepstake-style game. I tried them for the first time about a year ago, and since then, they’ve become one of the updates I’m most excited about. The mix of progression + that “maybe this spin is the big one” feeling hits differently.

How They Work: Instead of traditional paylines, these games use a “sweep” mechanic where winning symbols are collected and removed from the reels. New symbols drop down to replace them, and potentially creating chain reactions of wins. The progressive element comes in when you collect special symbols – each one contributes to a growing jackpot meter that can trigger at random.

What makes them special is that multiple players contribute to the same jackpot pool across different casinos, so the prizes can get massive. I’ve seen jackpots reach over £500,000 on some of these games. The sweep mechanic keeps the base game exciting because you can get 10-15 consecutive wins from a single spin when the cascades keep coming.

The RTP on progressive sweep slots tends to be slightly lower (around 94-95%) because part of your bet goes into the jackpot pool, but the trade-off is that massive win potential when the jackpot hits.

Slingo Games

Slingo is probably the most unique “slot” type on this list because its actually a hybrid between slots and bingo. I was skeptical when I first saw Slingo games, thinking it looked too complicated, but once you play a round, you’ll understand why they’ve become so popular.

How They Work: You start with a 5×5 bingo-style grid filled with numbers. Below the grid is a single reel with 5 positions (like a slot machine). When you spin, five numbers appear on the reel. If those numbers match any on your grid, they get marked off – just like bingo.

The goal is to complete lines (Slingos) on your grid – horizontal, vertical, or diagonal. Each Slingo you complete moves you up a prize ladder with bigger payouts. A full house (all 25 numbers marked) usually triggers the top prize or a bonus round.

What makes it exciting is the special symbols on the reel. Jokers let you mark off any number in the column above them, Super Jokers let you mark any number on the entire grid, and Devils block winning combinations. There’s real strategy involved in choosing which numbers to mark when you get Jokers.

I’ve had a couple of really good runs on Slingo — Riches and Rainbow Riches are the two I end up going back to. One time I started with £5 and somehow walked away with just over £200 after hitting a few full houses. The pace is what I like about it. You get a set number of spins each round, usually somewhere around 10 to 20, and the whole thing wraps up in a few minutes. It feels a lot more hands on compared to just spinning regular slots and waiting.

The RTP depends on the game, but most of the Slingo ones sit somewhere in the mid 90% range. They’re usually “medium volatility,” so you don’t end up stuck in those endless dead spins, but you still get enough ups and downs to keep it interesting.

Cluster Pays Slots

Cluster pays slots threw out the traditional payline system entirely, and honestly, it was about time someone did. These games have been around for a few years now, but they’re still considered “new” compared to classic slots.

How They Work: Instead of lining up symbols on paylines, you need to land clusters of matching symbols that touch each other – either horizontally or vertically. Most cluster pays slots require at least 5 matching symbols touching to create a win, though some need more.

When you form a winning cluster, then those symbols disappear and new ones then drop down from above (called cascading reels or avalanche feature). This can create chain reactions where you get multiple wins from one spin. I’ve had rounds where I got 15+ consecutive cascades, turning a £2 bet into £150+.

Games like Reactoonz, Aloha! Cluster Pays, and Jammin’ Jars are perfect examples. What I love about these slots is that massive clusters can pay ridiculous amounts – landing a cluster of 20+ symbols can trigger wins of 500x your bet or more.

The strategy element is interesting too. Some cluster pays games have special symbols that charge up meters or trigger modifiers when they’re part of wins. In Reactoonz for example, you’re trying to charge up the quantum meter to unleash powerful features that can clear half the grid.

RTP on cluster pays slots is usually solid (96-97%) and volatility ranges from medium to high. They’re brilliant for players who find traditional paylines boring.

Infinity Reels Slots

Infinity reels is a mechanic that genuinely surprised me when I first played it. The concept is simple but the execution creates some of the most exciting moments I’ve experienced on slots.

How They Work: These slots start with a standard 3×3 or 3×4 grid. But here’s the twist – every time you land a winning combination, an extra reel gets added to the right side of the screen. As long as you keep winning, new reels keep getting added infinitely (well, theoretically – there’s usually a cap around 10-12 reels).

Each new reel that gets added also increases the win multiplier, typically by 1x per reel. So if you manage to extend to 8 reels, you’ve got an 8x multiplier on all your wins. I once got a 10-reel expansion on Gods of Asgard Infinity Reels and walked away with a £680 win from a £3 bet.

The genius of this mechanic is that it flips the traditional slot experience. Instead of hoping for a bonus round, the base game itself becomes the main attraction. Every spin has the potential to turn into something massive if the reels keep extending.

Popular titles include El Dorado Infinity Reels, Gods of Asgard, and Steam Vault. The volatility is usually high because big wins require those extended reel runs, but when they hit, they really hit.

RTP is typically 96%+ and some versions offer a bonus buy feature where you can purchase guaranteed reel extensions, though these cost 50-100x your bet.

Hold & Win Slots

Hold & Win (also called Hold and Respin) has become one of the most popular mechanics in modern slots, and for good reason – I’ve had some of my biggest wins ever on these games.

How They Work: You play normally until you land 6 or more special bonus symbols (usually coins or orbs with cash values). This triggers the Hold & Win feature where only those bonus symbols remain on the screen, and you get 3 respins.

Each respin that lands another bonus symbol resets your respin count back to 3. The bonus symbols stay locked in place while empty positions spin. When you run out of respins or fill the entire screen, all the values on the bonus symbols get added up and paid out.

The real money comes from special symbols during the feature – jackpot symbols, multipliers, or symbols that collect all other values. On Money Cart 2 I once filled 14 of the 15 positions and hit a collector symbol that gathered everything for a £945 win from a £2.50 bet. My hands were literally shaking!

What makes Hold & Win so popular is that you can see your win building in real-time as more symbols lock in. Its incredibly tense watching those respins, hoping to keep the feature alive for just one more symbol.

Popular Hold & Win titles include Money Train 2, Buffalo King Megaways, and the entire Money Cart series. Volatility is typically high to extreme, and RTP ranges from 95-97% depending on the game.

Grid Slots

Grid slots are similar to cluster pays but different enough to deserve their own category. I started playing these properly about 18 months ago and they’ve grown on me significantly.

How They Work: Instead of traditional reels spinning, you have a grid (usually 5×5 or larger) where symbols drop into position from above. Matching symbols need to form specific patterns to win – this could be clusters, lines, or custom patterns depending on the game.

Winning symbols explode and then disappear, causing symbols above to drop down and potentially create more wins. Some grid slots add multipliers that increase with each consecutive win, while others have special symbols that modify the grid or trigger features.

What separates grid slots from cluster pays is usually the additional mechanics. Mines of Dalarnia has mining features where you break through layers of the grid. Plinko-style grid slots have symbols bouncing through pegs. There’s way more variety in gameplay compared to standard cluster pays.

My favorite is probably Reactoonz 2 which is technically both a cluster pays and grid slot. The 7×7 grid creates opportunities for massive 49-symbol clusters, and the feature triggers feel incredibly rewarding when you nail them.

RTP is usually 95-96% and volatility varies widely depending on the specific game. They’re perfect if you want something visually different from spinning reels.

Crash Games (Aviator-Style)

Crash games are the newest addition to online casinos and they’re technically not slots at all, but they’re marketed alongside slots and lots of slot players (including me) have gotten hooked on them.

How They Work: A multiplier starts at 1.00x and increases continuously – 1.50x, 2.00x, 3.00x, etc. You place a bet before the round starts, and you need to cash out before the game “crashes” and the multiplier stops. If you cash out at 2.50x, your bet pays 2.50x. If you don’t cash out before the crash, you lose everything.

The crash point is completely random – sometimes it crashes at 1.02x, sometimes it goes past 100x or even 1000x. There’s genuine skill involved in deciding when to cash out. Do you take the safe 1.5x profit or risk it for 5x?

I’ve played Aviator and JetX quite a bit, and the adrenaline rush is real. I usually set an auto-cashout at 2x to guarantee wins, but occasionally I’ll chase bigger multipliers. My best result was cashing out at 47x on a £5 bet for a £235 profit, although I’ve also watched it crash at 1.07x multiple times when I tried to get greedy.

What makes crash games addictive is how fast they are – a round lasts 5-30 seconds, usually. You can play 100+ rounds in an hour. The social aspect is cool too, with live chat showing other players cashing out or busting in real-time.

RTP is typically 97-99%, which is excellent. However, high-speed gameplay means you can burn through a bankroll quickly if you’re not disciplined. These games reward patience and risk management more than pure luck.

My Take on New Slot Types:

The innovation in slots over the past 5 years has been incredible. I still love classic slots and Megaways, but these new formats add so much variety to sessions. When I get bored with traditional slots, switching to Slingo or a crash game for 30 minutes completely refreshes my interest.

Try each type with small bets first to understand the mechanics. Some of these games (especially Hold & Win and crash games) can be way more volatile than they appear. But once you find the types you enjoy, they add a whole new dimension to your casino experience.

Funding the Online Casino Games

To play real money slots online, a player must be able to use the online payment system. This is not the case with land-based casinos where all the player can walk into a casino and play whichever slot game they want with cash. Unlike the land-based casinos, players cannot slip in the currency in the bill validator in online slot games. Instead, casino players are required to register on the online casino and add the necessary funds to their casino account before playing the slots.

There are several ways in which players can add funds to their accounts when it comes to online casino games. The following are just some of them:

Visa & Mastercard

Using Visa and Mastercard debit cards at casino sites is a fast and easy process and is the most popular option in the UK and around the world. Discover Leading UK Casino Websites

PayPal

PayPal is considered to be one of the most popular payment options when it comes to the transferring of electronic funds with online casinos. It is also one of the fastest way to withdrawal you winnings.

Neteller

The online financial service is known as Neteller, also allows players to open their online accounts to transfer funds to and from online merchants. This service also includes online casinos.

Bank Transfer

This service allows users to transfer funds from their bank account straight to their online casino accounts.

Other UK Payment options include:

• Google Pay
• Apple Pay
• ecoPayz
• Skrill
• Bank transfer
• Bank Wire
• Paysafecard
• E-wallets
• Maestro
• Trustly
• PayForIt
• Amex
• Cryptocurrencies
• Bitcoin casino payments

Are Online Games Random Like Land Based Casinos?

When it comes to randomness found in casino games, the regulations are the key and play a significant role in that factor. To know just how random a particular game is, one must find out who is regulating them. In the United Kingdom, where online casinos must have a license from the UK Gambling Commission to offer online gambling, the randomness is fair and well regulated.

We do not recommend any UK players ever playing at online casinos licensed by the Curacao gaming commission in the Caribbean; in our opinion, these Curacao online casinos are not trustworthy, and you might never get your winnings. Instead, only play at online casinos certifications by the UK GamblingCommission.gov.uk:

If players see that the games have been certifications by the UK GamblingCommission.gov.uk like all the casinos listed on casinos.org.uk, they can then feel completely safe. Other services that test for randomness are eCogra or GLI, iTech, or Gaming Associates. While the online games available in the US are required to live up to the expectations of the jurisdictions in which they operate in. For instance, Delaware, New Jersey, and Nevada are all extremely vigilant when it comes to the randomness of their land-based casinos, and the online casinos are overseen by the same regulatory bodies.

Thoughts On Social Casinos

Non-wagering social casinos are used by millions of players, who access them via social media outlets such as Facebook or mobile apps. These casinos are not regulated in the same way in which other wagering online casinos are regulated. There are no age limits for the players, and there are no restrictions on who gets to play the online casino and where they can play.

A big reason is that social casinos do not make any money with the online casino games that they provide. Secondly, there are no regulatory concerns when it comes to social casinos and whether the games are indeed random or not.

That being said, social casinos are not a non-profit organization with absolutely no interest in money. According to standard procedure, the social casinos will give players free credits every day, so if they want to play for free, they can, and no money will be charged. Players get to take advantage of the level up features as with other casino games. As the player moves forward, they get to unlock new slot games and continue playing.

Some slot players want to level up faster than their allotted free credits permit, or they may want to unlock and play premium games. This requires them to pay a small fee so that they can play those games. And this is basically how the social casinos make their money by charging a small fee to those who want to unlock their premium games. However, there is no cash-out feature, which means you can only buy more credits or unlock other casino games with your cash, but you’re not allowed to take the cash home physically.

Since the social casinos do not use real cash, the players use social casinos for fun, with only a minority of the players paying the fee to unlock additional games and features.

Quick Online Casino Slots Facts:

• Who is allowed to play is ultimately determined by the regulators of the country where the player is located.
• The UK Gambling Commission and independently run certification companies ensure the randomness of every online casino game in the UK
• Online casinos offer multiple ways for players to fund their accounts before they can start playing. This allows the players to buy more credits or take their winnings home.

More In-depth Casinos.org.uk Slots Guide’s by Popularity:

• Top-rated high volatility slot machines
• Best Slots Casinos
• List of Slots RTP
• Online Slots
• Beating The Slots
• All About Slots
• Play Free Slots
• Maximize Your Payouts
• Video Slot Machines
• Bonus Slot Machines
• How to Play Slots
• Slot Machine Faqs
• Progressive Slots
• Fruit Machines
• Loyalty Slots
• Infographic Types of Slots
• The History
• Mechanical slots

Other Online Slots Resources

Microgaming games one of the oldest internet slot machine providers.

https://en.wikipedia.org/wiki/Slot_machine good info on the History, Terminology and Technology.

https://www.gamblingtherapy.org/ Addicted to Online Slot machines. Help me site and forum

https://www.gamcare.org.uk/forum/people-slot-machine-addiction  UK help forum