Your Guide to the Best Online Slots

Slot games have been immensely popular for decades – in fact, it’s been over a century since the first machines were introduced to bars and saloons, making a huge splash from the get-go. Nowadays you don’t have to use an actual machine to play – you spin the reels with ease, online. In fact, online slots have ushered in several benefits that their land-based counterparts lack. For instance, you can:

There’s more where that came from – we’ve got additional resources for all the reel fans out there! So stick around while we lay out some other advantages of playing slots online on this page, and give you a detailed overview of the most popular game types and providers. Additionally, we’re set on saving you all the tedious research: you can look forward to receiving our hand-picked casino recommendations for online slots. If you’re hungry for more, browse through our related pages that will tell you about different slot game types, RTPs, historical tidbits, mobile slots and more!


Benefits of Playing Online Slots

There’s no secret to why so many people enjoy playing slots – they’re easy, low-commitment and purely chance-based, meaning you needn’t have any skills or use a strategy. We’ve already touched on a few prominent upsides to playing online slots, so let’s take a closer look at those and some other advantages.

Play around the clock: Online casinos are open 24/7, so you can spin the reels pretty much whenever you want. Whether in the middle of the night or just trying to fill a dull moment, good slot sites will always offer a fantastic selection of reels for you to pick from. Best of all, you don’t need to go anywhere to enjoy a few spins – you can play from the comfort of your sofa!

Huge selection of games: You’ll generally find a bigger selection of reels online than in any land-based casino, where obvious space limitations don’t allow for quite that many options. Many major online gambling sites offer upwards of 200 games, with the likes of William Hill hitting upwards of the 600 mark. That’s an extraordinary selection between the different slots categories, so you can rest assured that you won’t get bored with so many thrilling ideas and themes on your screen.

Play to win big: Another huge plus of real money slots online is having access to a bigger number of progressive jackpot games, including some astronomically high ones such as Mega Moolah or Mega Fortune. There’s over 150 progressive slots, whose jackpot pools grow progressively the more people wager. So cracking one of these might turn into a win of a lifetime, as it did for this lucky Mega Moolah winner.

Higher return percentages: Though not so obvious at first sight, this may be the biggest factor that has an actual influence on your chances of winning. While actual, land-based slot machines’ RTPs move in the upper 80s, most online slots enjoy return to player rates of at least 92%, with most being around mid-90s.

Slot Sites with the Best Jackpots

There’s currently tens of millions of pounds in jackpot games on the UK scene, most which can be attributed to online slots. As previously mentioned, game jackpot pools grow with each real money wager, but you may sometimes find a jackpot pool that is shared among several games, as is the case with Marvel’s Multi-Level Mystery Progressive Jackpot. This one is linked to several superhero online slots from the franchise and includes the Marvel roulette. Apart from slots and the occasional roulette game, other diversions such as blackjack also may appear as jackpot variants on some sites.

The jackpot slot game selection at a given gambling spot depends on which slot provider the site uses; Microgaming, NetEnt and Playtech are the usual suspects when it comes to big amounts, though you’ll find dozens of jackpot games from other software-makers as well. Most major casinos tend to offer reels from different providers, so you will, without a doubt, be spoilt for choice. We’ve detailed the main slots providers below, we’ve also provided a general overview of the main slot game providers and software developers on our casino overview page.


NetEnt have been on the scene since 1996, quickly rising to fame with their online gaming solutions in the early 2000s. With licences from Malta, Alderney and, of course, the UK Gambling Commission, this software giant provides some of the most sought-after games in the industry, such as Gonzo’s Quest or Starburst. They are also home to some of the biggest real money jackpots out there:

What sets this provider apart from the bunch is their cutting-edge graphical implementation, with crisp and lifelike graphics. Their games include tons of ultra-modern 3D slots, unconventional reels and original game themes.


This is another software powerhouse: an Isle of Man-based provider goes back to 1994 with their first online casino games. Since then, Microgaming’s repertoire has grown exponentially, serving land-based and online gambling spots alike. With Mega Moolah on their slot roster, this provider is responsible for the biggest jackpot win so far. You can try your hand at cracking this one at Casumo, one of our recommended slot sites. Here are some of the other big Microgaming wins.

Mega Moolah slot gameKing Cashalot from Microgaming

Ranking Game Amount Casino
1 Mega Moolah £13,213,838 Betway
2 Major Millions £1,536,290 Ladbrokes
3 King Cashalot £908,970 Mr. Green
4 Treasure Nile £307,430 Casino Cruise
5 Tunzamunni £51,938 32Red


Playtech’s gained quite a standing in the industry, raking in several eGR awards since their establishement in 1999. They also host the Marvel franchise games, with several slots as well as scratch cards and roulette, all of these sharing the same progressive jackpot pool. The biggest amount currently is Jackpot Giant, with over £3 million. Other highlights include Funky Fruits, Spamalot’s Holy Grail and Frankie Dettori’s Golden 7. Marvel’s Ultimate Power Jackpot is currently sitting on more than half a million pounds – which is definitely worth a spin!

Popular Games Online

Now that you’ve got a good overview of the biggest provider names on the slot scene (and on the igaming scene in general) and of the juiciest jackpots, let’s look at the most popular reels or slot game series that are enjoyed by thousands of gamblers around the world. Whether for their special features, design or RTP, each of these games is unique in its own way. For information on other types of popular games from these providers such as roulette or blackjack, check out our casino games overview!

Starburst reels and layoutStarburst winning lineStarburst game informationStarburst payouts


This eyecatcher will light up your screen with vibrant gems, mixing a futuristic vibe with some elements of classic fruit machines. As is the case with many NetEnt games, this one  has strikingly good graphics rendering an almost 3D-like feel, and it includes several fantastic special features:

The RTP is 96.10%, which can be described as an average-to-high when comparing to other reels available online. To get an impression of the game layout and rules, check out the slideshow to the right.

Thunderstruck II reel layoutThunderstruck II winning lineThunderstruck II Great Hall of SpinsThunderstruck II payouts


This Viking-themed slot is another crowd favourite whose popularity has also resulted in multiple follow-ups since its introduction onto the slot scene, such as Thunderstruck II, seen in the slider. The Thunderstuck series games offer several extra features – though we should mention that these are sometimes common among Microgaming games:

The RTP here is the same as with Starburst – 96.10%. As you can see, these mid-90s payout percentages tend to be rather common in online reels, giving players an obvious advantage over land-based slots.

Iron Man 3 reel layoutIron Man 3 payoutsIron Man 3 Hall of ArmorIron Man 3 Marvel Multi-Level Mystery Progressive Jackpot

Iron Man

We’ve also mentioned the Marvel Universe slots with progressive jackpot pools. Iron Man is one of them, enjoying such popularity that Playtech wasted no time with releasing other movie-based follow-ups as soon as possible. By now there are two versions of Iron Man 2 and one Iron Man 3, as well as some other spin-offs like scratch cards. The newest installment, Iron Man 3, features the following:

The RTP here is a little bit lower due to it being a jackpot game: we’re looking at 93.02%. While this is a slighlty lower than the average, it’s still much more favourable than what you’d find in land-based casinos.

Mobile Slots: Spin with Ease on the Go!

Playing on the go is a rapidly-growing subsection of online gaming which has experienced a sharp uptick in popularity with the faster-than-ever developments in portable device technology in the last years. Slot games have evolved immensely since their humble beginnings, with online slots now adapting not only to growing performance of smartphones and tablets, but of course also to various screen types. Many games are optimised for mobile use with simplified navigation commands and reel viewing that makes the most of your screen space.

The good thing about playing mobile slots is the game itself doesn’t require utmost concentration nor strategising, so it’s an incredibly effortless way to stay entertained during any dull moment. You don’t typically wager huge amounts per spin, so there’s no need to overthink things while you’re out and about. Obviously, you can play anywhere as long as you have a good internet connection, and with many operators providing HTML5 browser-based gaming apps, you don’t even need to download or install anything. If you’d like to experience top-notch mobile gambling with a huge selection of reels to boot, check out Mr. Green!

How to Play Online Slots on Mobile Devices

Native vs Download-Free Apps

Speaking of no need to download or install a gaming app, let’s take a closer look at what the similarities the booming HTLM5 format shares with the more ‘settled’ native (a.k.a downloadable) apps. They will of course both enable mobile gaming, and the types of online slots that you can access with one versus the other should be go unchanged for the most part. But while both formats enable your device to enter the game platform, they do it in different ways.

Resulting from the presence of download or a lack thereof, the amount of customisation differs. Native apps are tailor-made for each device and OS, and thus enjoy a better fit, so to speak. On the other hand, web apps can aim for a one-size-fits-all approach due to there being no download – but that may slow down the performance slightly and involves loading times. On the upside, HTML5-based apps and games can be reached by more operating systems than the usual Android or iOS options.

Spin this Way: Tips for Newbies

Slots are perhaps the easiest, least effort-requiring real money online games, so there are very few things in way of tips that we can give you that would significantly impact your game outcome, apart from familiarising yourself with the slot terminology. Nevertheless, here are some general guidelines.

Become a Slot Game Pro

Survey the RTPs

Man considering RTP percentagesKeep a good overview of the return to player rates in your favourite slot games, and inform yourself accordingly before you pick up a new slot to try. Though the RTPs in online slots are generally more favourable than on land-based machines, there may be a bad apple or two on the virtual scene as well, so double-checking when you choose is the best way forward.

Give Yourself a Budget

Man considering budget optionsJust because wagers per spin tend to be on the small side doesn’t mean you shouldn’t be careful about how much you’re spending. Afterall, even small amounts can add up to cause significant damage to your account if left unchecked, and this is particularly dangerous with slots. Best is to give yourself an allotted amount to devote to reel spins to avoid potential overspending.

Be Bonus-Smart

Man choosing a casino bonusMost sites offer welcome packages to new players (in addition to other perks for existing members) so there’s without a doubt plenty to choose from as a newbie. Nevertheless, not all bonuses are created equal, and some may be more beneficial to you than others. That’s why we advise you to always examine the number of play-throughs required to actually get the bonus paid out to your as well as the time allowed for this. The good news is, slots typically get a 100% wagering contribution towards the wagering requirement.

Play Jackpot Reels

Man being excited about a jackpot slotLastly, take advantage of the immense choice of jackpot games! Yes, you can win in other, ‘regular’ slots too, but why not go for the big one if you’re spending the cash anyway? You may just get lucky and join the long list of jackpot winners, perhaps even cracking the biggest one out there. There’s only so much that can be gained playing in demo mode. Start spinning for real money if you’re keen to win – we’ll be keeping our fingers crossed!

How to Spot a Bad Slot Site

We’ve talked at length about picking the right slot outlet and the best games, but how about mastering the tricks when it comes to spotting black sheep? Though most casinos have solid licensing and monitoring in place, there may be some – especially ones regulated offshore, with more lax requirements and less thorough auditing – that employ some cheeky tactics to get the most out of their players. These are some things to watch out for when scouting for your next slot casino:

Our advice is to stick with the casinos recommended on our site or other major operators that are fully licensed in the UK market and thus comply with all regulations and player protection measures. In terms of RTPs, look for mid-90s for standard, non-jackpot variants and don’t go below 90%. For more details on how to avoid scams and unreliable gambling operators, take a look at our safe casinos guide!

Practice with Play Money!

If you’d like to get a head start on a game without spending any funds first, you can make good use of the practice play mode, offered by several major online operators. This will allow you to use play money to spin the reels a few times while you get the hang of the game, its rules and features. has more than enough slots in practice mode – for some of which you don’t even need to be a registered member. So go on and test out the reels!