What are Online Slots?

Playing online slots games is one of the most well-known forms of gambling at casinos and will be familiar to anyone who has ever played a fruit machine. It involves trying to win real money by spinning virtual reels and hoping you land a winning combination of symbols on a payline.

While slots are easy to play, each online casino slot has its own rules regarding winning combinations, payouts and bonuses. Slots also come in a variety of types, and can involve simple three-reel formats that offer fast-paced gameplay to modern progressive jackpots with eye-catching top prizes.

Virtually all UK online casinos have slots, but the best online slots sites have thousands of slot games to choose from, to cater to all player preferences and budgets.

Top 5 Slots at UK Casinos for April 2025

With thousands of online slots to choose from these days, knowing where to start can be difficult. To help you out, here are our top five fun and popular slots available to play at the best UK gambling sites:

Rank	Slot	Provider	Min. Bet	Max. Win	RTP	Available at
🥇	Gates of Olympus	Pragmatic Play	£0.20	5,000x	96.50%	LeoVegas
🥈	Big Bass Bonanza	Pragmatic Play	£0.10	2,100x	96.71%	JackpotCity
🥉	Sweet Bonanza	Pragmatic Play	£0.20	21,175x	96.51%	Neptune Play
#4	Book of Dead	Play’n GO	£0.01	5,000x	96.21%	Dream Vegas
#5	Starburst	NetEnt	£0.10	500x	96.09%	Pub Casino

Types of Online Casino Slots

When you visit a casino for the best slots to play online for real money, there are several different types you’ll come across, which are each enjoyable to play but work in different ways as follows:

• Classic Online Slots: Slot games in a ‘classic’ format often feature a three-reel layout with 10 or fewer paylines and have limited to no in-game bonuses. These casino slots are designed to enable simple and quick gameplay that’s easy to follow.
• Video Slots: These online slots use 3D graphics and immersive soundtracks to convey the theme, and will likely come with features such as wilds, multipliers, free spins and mini games to add to the excitement and offer boosted chances to win.
• Progressive Jackpot Slots: These online slots have a live jackpot, which increases in real time whenever a player places a wager on the game. The biggest progressive jackpots boast multi-figure top prizes, such as the famous Mega Moolah series.
• Penny Slots: Some casino slots allow you to place bets starting at just a single penny per spin. They are designed to cater to low-budget players and allow you to enjoy the fun of online slots without risking large amounts of money.

Popular Online Slots Themes

The best UK online slots come in a variety of themes too. Here are some of the most common you’ll come across:

• Ancient History: There are dozens of beloved video slots set in locations and times such as ancient Greece and Egypt. These slot games often have recognisable characters that can appear on the reels and activate bonuses, such as Greek gods or iconic rulers like Cleopatra.
• Branded Slots: Many real money online slots are based on popular films, TV shows and bands. For instance, you can hit the reels on Game of Thrones by Apricot (formerly Microgaming), The Godfather by Light and Wonder, and Guns N’ Roses by NetEnt.
• Mythology: There are many casino slots with a fantasy-inspired theme involving epic quests, witches and wizards and magic. Top-rated mythology slots include Goblins and Gemstones by Kalamba Games and the Red Tiger Gaming release Dragons Cluster Buster.
• Wild West: Get your sheriff’s badge and cowboy hat at the ready, as lots of online slots transport you back to the wild west for the chance to win some serious loot. Wild west slots include Tombstone RIP by Nolimit City and Big Time Gaming’s Outlaw.

Top Tips for Playing Online Slots

It’s important to remember that casino slots are games of chance and there’s no way you can guarantee a payout. However, there are tips you can follow to improve your odds of winning and enhance your enjoyment while you play:

• Take advantage of casino bonuses that you can use on UK slots, such as free spins. These give you more chances to win when you play online slots, and some casinos offer promotions that don’t require a deposit, such as no deposit free spins.
• Look out for online casino slots with a high return to player (RTP) rate. The average RTP for slot games is 96%, so slot games with a higher RTP than this can be expected to pay out more often on average.
• Try out free casino games to play demo versions of online slots before you stake real money. This will help you gain an understanding of how the slot works (and whether you enjoy playing it) without the risk of losing your cash.
• Gamble responsibly whenever you play online slots for real money by setting yourself a budget beforehand and sticking to it. The fast-paced gameplay of casino slots online can make it easy to quickly accumulate losses, so it’s important to stay in control of how much you’re betting.

What Our Best Online Slots UK Casinos Offer

Finding great UK-based online slots casinos isn't rocket science, and it's simply a matter of knowing what to look for. Our online slots experts have tested licensed sites available in Britain to find the absolute best slots sites, and we're happy to share our methods and findings with you.

It's important that you know what makes for a great gambling experience. All of our recommended slots casinos:

• Are regulated and licensed by the Gambling Commission (UKGC)
• Use advanced encryption measures to keep you safe
• Offer excellent customer service by phone and live chat
• Have a vast library of casino games including the best online slots
• Accept the most secure banking methods for efficient deposits and fast withdrawals

What Are the Most Popular UK Online Slots?

While there are thousands of video slots to choose from at our top-rated casinos, the following slots games are among the most popular with UK players:

• Mega Moolah: This safari-themed progressive online slot offers one of the largest top prizes you’ll find at any online casino, and its Mega Jackpot regularly hits eight figures. A lucky UK player won £12.9 million playing Mega Moolah in October 2015.
• Starburst: The colourful 2012 video slot by NetEnt set in outer space is among the most played slot games worldwide. You can bet anything from 10p to £100 per spin with a top prize of 500x your bet.
• Book of Dead: Play’n GO’s iconic casino slot series starring the fearless explorer Rich Wilde started with this 2016 release. Set in an ancient Egyptian temple, the game has a top prize of 5,000x your stake and an exciting double or nothing gamble feature.
• Big Bass Bonanza: The original online slot in what has since gone on to become a beloved fishing-themed franchise, Big Bass Bonanza has an above-average RTP of 96.71% and features a free spins bonus with a progressive multiplier.
• Double Bubble: This sweets-themed UK online slot from Gamesys has a top prize of 20,000x your bet, alongside in-game bonuses including wilds, multipliers and two mini games.

Progressive Jackpot Online Slots

If you want to chance to win the most lucrative prizes playing UK slots online, we suggest checking out progressive jackpot slots. These video slots feature real-time prize pools that grow with every real money spin of the reels, until a lucky player hits the jackpot.

The biggest progressive jackpots, such as the Mega Moolah and Age of the Gods series, have top prizes that regularly hit seven or eight figures. You can see the latest jackpots up for grabs on top online slots in the UK below:

Play Online Slots Games for Free

There are plenty of options if you're looking to play online gambling slots for free. No deposit bonuses let you play the best slots online in the UK without having to deposit any money, so you have the chance to win big without any financial risk.

Alternatively, many slots casinos let you play slots for fun in demo mode. This is a good way to try slots out and see which games you like best, or simply enjoy all the excitement an online slot has to offer without worrying about your bankroll.

Online Slots on Mobile

There are thousands of action-packed online slots you can play at top mobile casinos in the UK. All you need to is load the casino’s mobile site on your smartphone internet browser, or download the dedicated casino app to your iPhone or Android.

The best mobile casinos are home to the latest and most popular slots, as well as occasional exclusive bonuses that you can use on online slots. Best of all, these days most slots are produced using HTML5 technology, so they’re designed to run quickly and smoothly across all smartphone devices.

Conclusion: Play the Best Online Slots

There are so many reasons to enjoy slots online, whether you’re trying to win real money or simply playing for fun. The sheer variety of types and themes available means they easily cater to all player preferences and budgets, while many slots sites offer regular bonuses that you can use on slot games for extra chances to win.

Lastly, if you enjoy trying to land the biggest prizes up for grabs at online casinos, progressive jackpot slots are the obvious place to start.