Online slots make up sixty percent of all the money made from online gaming in the UK. This is more than live casino games, table games and sports betting. There are thousands of online slots across casinos. So how do you choose where to play? This can be tricky. Here is what you should expect from any casino that is licensed by the UK Gambling Commission (UKGC). All slots must be checked by a company. The random number generator (RNG) must pass tests. The casino must also say how much money the game pays back over time. This is called the RTP. The UKGC says this must be at least seventy percent.. Most slots I have played pay back between ninety-four percent and ninety-seven percent. If a game pays back less than ninety-four percent that is a warning sign. When you play at a UKGC casino you can be sure that the results are random and the RTP is correct. If you play at a casino that is not regulated by the UKGC you have to trust a regulatory body, like the one, in Curaçao. I would rather play at a UKGC casino.
By Lisa Schamberger, Seasoned Casino Reviewer
Ranked by slot library quality, RTP transparency, mobile performance, and bonus value.
RTP equates to the percentage of money a slot pays back over thousands of spins. The higher, the better. These ten titles offer the best theoretical returns I could find at UKGC casinos in March 2026. Does a high RTP guarantee success? Not necessarily — volatility can be extreme. I have lost thirty pounds on a 99% RTP game in twenty minutes. But over time? The odds are in your favour with these.
| Slot Game | Provider | RTP | Volatility | Notes |
|---|---|---|---|---|
| Mega Joker | NetEnt | 99% | High | Classic fruit machine, Supermeter mode required for 99% RTP |
| Blood Suckers | NetEnt | 98% | Low | Vampire theme, consistent payouts, excellent for steady play |
| White Rabbit | Big Time Gaming | 97.72% | Very High | Alice in Wonderland theme, expanding reels, massive max win potential |
| Dead or Alive II | NetEnt | 96.8% | Very High | Wild West, Train Heist feature, extremely popular with UK players |
| Sweet Bonanza | Pragmatic Play | 96.51% | High | Candy theme, tumble mechanic, multiplier bombs in free spins |
| Legacy of Dead | Play'n GO | 96.58% | High | Egyptian theme, expanding symbols in free spins — sequel to Book of Dead |
| Gates of Olympus | Pragmatic Play | 96.5% | Very High | Zeus theme, tumble mechanic, multipliers up to 500x — most-played slot in 2026 |
| Book of Dead | Play'n GO | 96.21% | High | Egyptian explorer theme — one of the most consistently popular UK slots |
| Starburst | NetEnt | 96.09% | Low | Classic jewel theme, low volatility — best for beginners and bonus wagering |
| Wolf Gold | Pragmatic Play | 96% | Medium | North American wildlife theme, Money Respin feature, popular jackpot slot |
RTP figures are theoretical averages calculated over millions of spins. Individual session results will vary significantly. Always gamble responsibly.
The type of games you find at a casino really depends on the companies they work with. Here are the top six companies that make games that people in the UK love to play in 2026.
NetEnt makes the best slots. Their games have pictures, cool bonus features and some of the best payouts. You can play Starburst, Blood Suckers, Dead or Alive II and Mega Joker at every casino in the UK. NetEnt is now part of the Evolution Group.
Pragmatic Play is one of the companies that make slots in the UK. People love playing Gates of Olympus, Sweet Bonanza and Wolf Gold. They come out with games every two weeks and the payouts are usually very good between 96% and 96.5%.
Play'n GO is great at making slots that're thrilling and have stories. Book of Dead and Legacy of Dead are two of the most played slots in UK casino history. Their games are made to be fun which is why they have grown fast since 2023.
Evolution bought Red Tiger in 2019. They keep making slots. Red Tiger games are known for having jackpots that pay out at certain times every day. People in the UK love this kind of game.
Microgaming is one of the companies that make games for casinos. They made Mega Moolah, which's still the biggest jackpot game. Even though new companies have come out Microgaming games are still available at UK casinos.
Big Time Gaming invented the Megaways way of playing which can make thousands of ways to win on one spin. They made White Rabbit and Bonanza. Other companies like Pragmatic Play and NetEnt also use the Megaways way, which makes Big Time Gaming a big player, in the slot game business.
RTP is the most important number to know when playing online slots. Here is how it works in the UK.
Return to Player is the percentage of all money put into a slot that the game is designed to give back to players over a long time. A slot with 96% RTP will give back £96 for every £100 put in. The remaining £4 is the casinos profit.
The UKGC says that all online slots at UK-licensed casinos must have an RTP of 70%. In reality most slots have a higher RTP. Between 94% and 97%. The UKGC also requires that RTP be shown for every slot game so you can always check before playing.
RTP tells you how much you can expect to get in the long run. Volatility tells you how often and how much you can win in the short term. A slot like Starburst (96.09% RTP) gives out wins often. Good for using bonuses. A slot like Dead or Alive II (96.8% RTP) gives out bigger wins less often. Better, for players chasing big wins. Both may have similar RTPs but feel very different to play.
Every slots RNG must be checked and certified by an independent lab before it can be used at a UKGC-licensed casino. Approved labs include eCOGRA, iTech Labs, BMM Testlabs and GLI. This makes sure that the results are truly random and not controlled by the casino.
Both formats have a place in any UK player's game selection. Here is an honest comparison to help you decide where to focus.
→ Read our full guide to live casino UK 2026 for a detailed breakdown of the best live dealer sites.
→ For the best bonus offers on slots, visit our casino bonuses UK guide.