The Best Online Slots Sites of August 2022 Are Here!

Bright lights, buzzing, high-pitched pinging and the sound of coins clattering into the metal payout tin, casinos just wouldn’t be the same without slots.

These days, ‘one-armed bandits’ take up 80% of the game rooms in Las Vegas, and are truly the in-vogue entity on the casino floor, and that’s the same online. Slot machines are great fun, and the chances of winning are pretty favourable too.

Developed in Brooklyn, New York in the late 1800’s, slot machines were often on the periphery of the casino floor during their formative years and were treated with little regard by most casino owners. In fact, for the most part, slot machines were used exclusively by the wives of the table-game players as a way to stifle their boredom.

Today, slot games have never been more popular, especially at UK online casinos which are packed to the rafters with all different types of slots with huge companies like Universal, HBO and MGM all clambering to get involved in the market.

For the player, there’s never been a better time to be a slot player. Whereas with traditional table games like roulette, poker, baccarat and blackjack your wins are mostly incremental, when playing slot machines you could win tens of millions with just a few pence.

Games like Mega Moolah and Mega Fortune have become known in the casino world for pouring out huge wins from tiny stakes, and with the competition only likely to become more and more fierce, the jackpots are only going to increase and increase.

Types of Slot Games & Slot Machines

  • CLASSIC SLOTS – Classic slots are the traditional slots with 3 reels which you would play like any other slot
  • VIDEO SLOTS – Video slots a lot more elaborate than classic slots and feature anywhere between 1 and 100 lines
  • MEGA SPIN SLOTS – These are the slots where you play between 3 to 9 slot machines at once
  • PROGRESSIVE SLOTS – These are the slots that make everyone excited as these are the slots with the biggest jackpots
  • FRUIT MACHINE SLOTS – Fruity’s are like classics but only feature fruit symbols
  • 243 PAYLINE SLOTS – 243 payline slots offer the most paylines out of any slot on the internet
  • VEGAS SLOTS – These are online replica’s of the slots you’ll find in real, brick and mortar Vegas casinos

In the below table we look at the casinos offering the best games, the casinos offering the most variety of games, and we also take into account the UK casinos offering the best promotions on their featured slot games.

Some of our selected casinos only offer slot game by a certain software provider which may sound limited, but these type of casinos have tons of exclusive slot games to boot.

However, conversely, we also showcase the casinos that offer a number of different software providers. On these type of casinos, you’re likely to see a whole eclectic mix of games with plenty to choose from.

Whatever you’re looking for from your slot – the big wins, the fun bonus rounds, the beautiful graphics – we have you covered. Have a browse through our ever-evolving, constantly updated table below and read the reviews for more detail so you can find your best-matched slot haven.

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House Edge

House Edge

The house usually has an edge of between 3% and 12% in online slots, and the all the casinos that are featured on Casino Circle have minimum payouts which will all be explained on the site’s terms and conditions page.

Betting Options

Betting Options

Winning symbols are selected using a random number generator. Some winning combinations are designed to appear more than others, but, slots aren’t programmed to blow hot and cold so theoretically, a jackpot could appear twice in the same day.

Betting Odds

Betting Odds

Online slots have big payback percentages and the average payback online is actually higher than what you’ll find in a brick and mortar casino. Most online casino’s payback is 99%, and should explained on the casinos terms and conditions page.

Looking for good bonuses on UK slot games, are we?

Is it the bright flashing lights? Or the ambient dissonance of spinning and winning? It could be Las Vegas where the classic 'one-armed bandits' have become synonymous with the casino capital and the numerous movies and TV shows featuring them. Whatever image your mind conjures, slot games are always popular. As times change, so do players' habits and the shift from real casino play to online slot machines continues to gain momentum.

Casino Circle is here to steer you through that heavy stream of UK online slot games and help you find the best ones to play.

A history

The precursor to the modern slot machine was created by Sittman and Pitt of Brooklyn, New York in 1891. The machine had five drums and 50 card faces as a solo version of poker. The basic premise involved sticking a nickel through the slot, pulling the "arm" and trying to get the best poker hand you could. But as you couldn't gamble for money, winners were awarded certain prizes in exchange for good hands.

German-American Charles Fey improved Sittman and Pitt's model and created what we know as the modern slot machine. He reduced the amount of reels to and changed the cards to symbols, using horseshoes, diamonds, spades, hearts, and a Liberty Bell which gave the machine its name. This simple format still exists today. The symbols often change but classic slot games still use the bell from the original.

From there, slot machine manufacturers tried to avoid US gambling laws against illegal cash prizes by offering chewing gum in exchange for wins. Fun fact: the Bell-Fruit Gum Company used on some old slot machines is where the BAR symbol comes from. By the 60s, the first fully electromechanical slot machine was developed and a decade later, the first video slot was made. The rest is slot history!


Slot game or slot machine are the general terms used globally but there are some words used in different countries.

  • The term slot in slot machines refers to the money slots where players insert their coins before pulling the lever or pressing the Spin button.
  • In the UK, fruit machines are the physical variant named after the fruit symbols you'd find on the spinning reels: usually lemons, cherries, oranges, grapes, and watermelons.
  • Scotland refer to them as puggies, possibly related to its use as term for the kitty in card games and, later, a slang term for a cash machine or ATM.
  • In Australia and New Zealand, they're called poker machines or pokies.
  • Japan call them pachisuro or pachislo which is a combination of pachinko and "slot machine".

Online slot games today

Slot games are very popular, arguably more than the machines "in the wild". That's why major corporations have jumped in with licenced games for the likes of Jimi Hendrix, Guns N' Roses, Vikings, and Jurassic Park. But why? Well, there's the variety. Here at Casino Circle, we provide all kinds of UK slots, in 2D and 3D, with set jackpots and progressive jackpots, classic and new. There's no need to leave the house as you can play on any device with internet access. And you don't have to break the bank to start. If luck is on your side, you could win millions from a spin worth less than £1. That's a better return than the National Lottery!

Going back to those game types, here is a brief summary of what they are:

  • Classic Slots - Essentially the same format as the original Liberty Bell slot machine: standard 3x3 reel
    • Fruit machines - A thematic variant, with fruit symbols instead of card symbols
    • Vegas - You would have seen the slot machines from Vegas with the giant lever - those but in an online form
  • Video Slots - The possibilities are endless with video slots. The paylines are increased as well as the effects and bonus games
    • 243-payline - 243 payline slots offer the most paylines out of any slot on the internet
    • Progressive - The big winning slots - this is where the jackpot grows and any player has the potential to win million


With all the talk of winning millions, it's important to know how much slot machines are likely to pay out over time. Old slots had 3 reels and 10 symbols which gave 1000 possible combinations. As the chance of any combination was 1 ÷ 10 x 10 x 10 = 0.01%, jackpots were lower and became boring after a while. Now, most video slot games have 5 reels and certain symbols are weighted in their probability of appearing, increasing the combinations and allowing for bigger jackpots.

UK slot machines are programmed to pay out a certain percentage of money put in. For slot games we feature, that percentage is usually between 88%-97%. This is called the RTP or "return to player". We calculate them slightly differently. We take the RTP away from 100% and that is called the "house edge", as that's the "edge" the "house" (ie. casino) gets back. Anything over 5% for a house edge is considered "high" and means you'll need to put a lot in to get it back over time.

Example: Millionaire Genie has a house edge of 4.98%. If you were to place a £1 bet for 100,000 spins, you would win back £95,020 on average, and the casino would keep the remaining £4,980.

Probabilities of certain symbols falling on the paylines are determined by PRNGs or Psuedo Random Number Generators. More sophisticated PRNGs continue to generate different combinations even when the game isn't running to prevent players from predicting the next spin outcome.

Disclaimer: Online gambling is illegal in some jurisdictions. It is your responsibility to check your local regulations before gambling online. Only players over 18 years old can register at online casinos. Playing online casinos, slots or bingo should remain a form of entertainment.

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