Jackpot Slot Machines – The Ultimate Guide

For any budding slot fan, the very mention of the word, ‘jackpot’, is enough to turn legs into jelly. So, you’d better take a seat before you plough on through this article. Buckle up, as we take you on a journey to find the biggest and boldest online jackpot slots known to man. Along the way, we’ll be contributing comprehensive context on the types of jackpots and typical gameplay features you’ll encounter.

Jackpot slot machines are older than your granddad. The first machine was built in 1881, and aligning the same symbols earned you a beer or a cigar, or whatever was available in the establishment. Slot machine mechanisms have also been employed to dish out tasty treats to navigate cash-based gambling bans. Jackpots have come and gone in all shapes and sizes, and the road to the first multi-million-pound, mobile-based, online jackpot was no plain sailing. Through the years, these new prizes necessitated different kinds of machines and technological developments. As technology facilitated the linking of different machines in casinos, and even around the world, bigger and bolder kinds of jackpots became conceivable.

Types of Jackpot Slots

Ignoring the early jackpot slot iterations which belched out gum or tokens, we’re going to focus on the real money jackpot slots you’ll find in the libraries of copious online casinos. Online slots are defined by the types of jackpots they spew, and nowadays the sums of money on offer vary from modest to life-changingly ridiculous. Mega prize-pools can now be accumulated from contributions of millions of players around the world, simultaneously, while some loners offer smaller, fixed sums that aren’t shared with their slot machine brethren. The difficulty of hitting the jackpot varies accordingly, as does the frequency of payouts. Let’s look at the main types of jackpots out there.

Flat Jackpots

An image from Jack and the Beanstalk slotFlat jackpots don’t sway with the wind: the big prize remains the same no matter how much cash it has consumed. Often referred to as non-progressive jackpot slots, or ‘flat tops’, these games tend to have quite a low ceiling for potential wins, but the frequency is normally higher. You might find these on that fruit machine in the corner of your local pub, but plenty of online slots also feature flat jackpots. Examples include Jack and the BeanstalkGonzo’s QuestDa Vinci Diamonds and Thunderstruck 2.

Stand-Alone Progressive Jackpots

A Break da Bank game imageJust like flat jackpot slots, stand-alone progressives have absolutely zero jackpot connection to their slot machine brethren. While the prize pool is not shared with other games, it differs from the flat jackpot machines in that a percentage of the money wagered by punters is added to a fixed jackpot, which is granted for the highest winning combination. In other words, somewhat of a hybrid between a flat and a progressive jackpot. A popular online example would be Break Da Bank.

Proprietary Progressive Slots Jackpots

Imagery from the famous Cleopatra slotProprietary progressive slots jackpots are jackpots shared across slot machines which are operated by the same firm, in the same brick and mortar gambling locale. The jackpot is shared across various games or variants of the same game in land-based casinos. Consequently, the jackpots grow much larger than those of a stand-alone progressive jackpot machine. These jackpots can also occur across various locations of the same casino group, for instance Grosvenor casino in Birmingham and Manchester could share the same pool.

Wide Progressive Jackpots

The DC Super Heroes Jackpots logoWith a jackpot shared between various titles, these beauties offer the highest jackpots out of any slot machine. On the flip side, the chances of winning are lower than on any slot machine. These are the machines for the dreamers out there. If you have time and money to burn, you might just witness something crazy. The jackpots on offer are truly life-changing sums of money. The DC Super Heroes Jackpot, including Batman and the Joker Jewels is a prime example, as is IGT’s MegaJackpots, shared between several games.

Typical Gameplay Features – Free Spins, Bonus Rounds

A second-screen bonus round in the Foxin' Wins slotMany slots with progressive jackpots require you to wager the highest possible coin denomination to be eligible for the main jackpot. Lesser prizes are still available, but you wouldn’t be able to get hold of that life-changing sum of money. Despite this, the variance of gameplay features is minimal among the different types of jackpot games. Almost all slot machines incorporate a random number generator, which means the outcome of the game is totally random and independent of previous results.

Traditional flat jackpot slots, like classic fruit machines in a UK pub, often came with special buttons like nudges and holds. However, such features are not limited to non-progressive jackpot slots. Video slots featuring free spin bonuses and second-screen bonus rounds, like Foxin’ Wins, tend to come with progressive jackpots, although this is not always the case.

Record-Breaking Jackpot Slots

Now that you can potentially win millions on a screen smaller than a baboon’s backside, it’s pertinent for us to provide you with some context and a clear overview of the online jackpots on offer. Online jackpot records have not yet the heights of the largest land-based hauls, but they are catching up. The world record slot jackpot remains the $39 million won at the Excalibur Casino in Las Vegas in 2003, but with the increasing number of online slot fans out there, it would be no surprise if the record is broken online one day.

An infographic showing the biggest slots jackpot wins ever

Around 85% of online casino punters play on mobile devices, and the vast majority of the games on offer tend to be slots. It comes as no surprise then, that mammoth jackpots are being won left, right and centre on smartphones and tablets. As the slot on which the record mobile slots jackpot was won, Microgaming’s Mega Moolah once again proves it is exceedingly aptly named. The anonymous punter won £7.1m in August 2016. Other huge mobile-based wins have been recorded on Mega Fortune (£6.8m), and Jackpot Giant (£4.5m).

Casino Jackpot Slots Online vs. Land-Based

The crucial difference between online and land-based casino jackpot slots is the return to player (RTP) rate. Online slots pay out more frequently, or the wins give out more money per hit. With an average RTP rate of 95-98%, online slot payout ratios are more generous than land-based casinos because they can afford to be. For example, they don’t have to pay for a location to house the slot machine, unless you count web hosting. However, the higher RTP rate does not mean the jackpots are higher.

The most popular land-based slot machines, such as Cleopatra and Megabucks, are often transmogrified into online equivalents, although the aforementioned examples are synonymous with the super casinos on the Las Vegas strip. The Megabucks slot machines in Vegas were the first to link machines together to form a proprietary progressive slot jackpot. The trend continued with the implementation of hundreds of proprietary progressive or wide-area progressive jackpot slots in brick and mortar casinos. However, this is an area where online jackpot slots really thrive. Nowadays, you can find jackpot pools shared between a gargantuan glut of online games, and often in various casinos simultaneously. A top slot developer such as Playtech or NetEnt can unleash their multi-title, shared jackpot prize on a staggering number of operators, which explains why progressive jackpots increase more rapidly.

Presumably, you are reading this because you consider yourself a bit of a reel-spinner, but you might not know the best places to find the biggest jackpots online. With hundreds of casino jackpot slots online, it can be a minefield, so it’s wise that you came searching for advice. Check out some more top online jackpot slots below.

We’ve included plenty of online casino reviews on this website, plus an overview of the world of online slots, which can also help you decide on the best place for you to achieve your jackpot dreams. There are a whole host of jackpot tracking sites out there, to help you find the current amounts on offer. It’s also possible to play demo versions online to get a good feel for a game, however, you’ll need to sign up and wager real money in order to win the jackpots.

Last Updated on 2 Jul 2021 by Mark Podd