Online slot jackpots have been increasing in value over recent years, and more millionaires are being created than ever.

As the popularity of progressive jackpots grows, and accessing online slots on tablets and smartphones gets easier, expect those prizes to keep on climbing in 2019.

So, who were the big jackpot winners in 2018? Let's switch on the progressive tracker and find out.

Game: Mega Moolah (Microgaming)
When: September 2018
Amount won: €18,910,668

Let's kick off with another record-breaker: Mega Moolah.

Mega Moolah is one of Microgaming's most enduring online slots, a slick African-themed game where players of all wallets can trigger the prize wheel at random.

Line up the wheel arrows and you can take down one of four jackpots. The biggest jackpot seeds at £1m, but such is the popularity of Mega Moolah that the mega jackpot regularly surpasses that total.

You will find Microgaming's Mega Moolah slot in the Betway Casino lobby. In fact, Betway boasted the previous world record for a progressive jackpot when Jon Heywood won £13.2m playing the slot.

That record was left unbroken until this year when one lucky player hit Mega Moolah for a cool €18m prize.

Game: Jackpot Giant (Playtech)
When: October 2018
Amount won: $12.3m

It wasn't just Microgaming who enjoyed all the jackpot headlines in 2018.

Playtech got in on the act in October when one lucky player hit the Jackpot Giant progressive for a cool $12.3m.

The 3D online slot from Playtech follows a jolly Incan chief as he goes about his day, filling the player's wallet with cash. If you bet the maximum amount, you can qualify for the progressive jackpot. Simply hit five wilds on the first payline and the jackpot is yours.

Game: Joker Millions (Yggdrasil)
When: November 2018
Amount won: €7.8m

Smaller developers like Yggdrasil Gaming are becoming popular with players because of their slick games and unique bonuses.

So it's good to see Yggdrasil Gaming claiming one of the top jackpot spots in 2018. In November, one casino player from Sweden took down the Joker Millions top jackpot for a massive €7.8m payday.

Joker Millions has only been around since 2015, and the €7.8m prize is easily the biggest ever jackpot seen in the game. Two slot jackpot records for two developers in 2018; what does 2019 have in store?

Game: Mega Fortune (NetEnt)
When: July 2018
Amount won: €5,996,418

With the publicity surrounding Mega Moolah's heroics in 2018, it's easy to forget that NetEnt's Mega Fortune once held the world record for a progressive jackpot (€17.8m back in 2013).

But the online slot that celebrates the rich and famous can still cause a few surprises. In the summer, one player took away the game's mega jackpot for almost €6m. Mega Fortune also features two smaller jackpots. It's a game that really caters for players with a range of bankrolls.

Game: Mega Moolah (Microgaming)
When: June 2018
Amount won: $8,332,379

Before September's record-breaker, there was still time for someone to win a life-changing amount of cash on Mega Moolah.

The average mega jackpot payout on the slot is around the $5.3m mark, but that total was well and truly smashed in June when one player won an $8.3m pot.

Jackpot King (Blueprint Gaming)
When: November 2018
Amount won: $2,003,288

At the lower end of the scale, there were still some impressive progressive wins on Blueprint Gaming's Jackpot King range.

Jackpot King is a linked progressive that is featured in slots like Top Cat, Slots O'Gold, and Irish Riches Megaways.

And in November, one lucky player scored a jackpot worth over $2m. To trigger the jackpot, players must land five Jackpot King symbols. A second screen bonus will then launch in which the player must land the special symbols or spin a prize wheel.

Play the best progressives at Betway Casino

You will find plenty of progressive jackpots in the Betway Casino online slots lobby. Remember, you can try out lots of online slots without risking a bankroll.

Play today and see why progressives are such hot property.