Best Online Slots: The Most Popular Games and Why Players Love Them

Thousands of slots are released every year, but only a few become classics that players come back to again and again. Here are some of the most popular online slots of all time, what makes each one stand out, and how to find a game that suits you.

The figures below are the providers’ standard versions. Some casinos run lower-RTP versions of the same game, so always check the paytable where you play.

Starburst (NetEnt)

Released in 2012, Starburst is simple, bright and fast. It has 10 paylines that pay both ways and expanding wilds that trigger re-spins. RTP is about 96.1% with low volatility, so wins come often but are usually small – ideal for relaxed play and for clearing bonus wagering.

Gonzo’s Quest (NetEnt)

Gonzo’s Quest made the “avalanche” mechanic famous: winning symbols explode and new ones fall in, with a multiplier that grows with each cascade. RTP is around 96% and volatility medium.

Book of Dead (Play’n GO)

The best-known “book” slot follows explorer Rich Wilde in ancient Egypt. During free spins, one symbol expands across the reels, which can create big wins. RTP is about 96.2% with high volatility. If you like this style, try our reviews of Book of Aztec and Book of Pharao.

Mega Moolah (Microgaming)

Mega Moolah is the most famous progressive jackpot slot. Its Mega jackpot starts at £1 million (or the local equivalent) and has paid record wins of more than €18 million. The base game is modest, but every spin has a chance to trigger the jackpot wheel. Read our Mega Moolah review.

Mega Fortune and Age of the Gods

NetEnt’s Mega Fortune and Playtech’s Age of the Gods series are other long-running jackpot favourites, each with several jackpot levels. More about how they work in our progressive slots guide.

Bonanza (Big Time Gaming)

Bonanza introduced Megaways in 2016: the number of symbols on each reel changes every spin, giving up to 117,649 ways to win. Cascades and an unlimited free spins multiplier make it highly volatile.

Sweet Bonanza and Gates of Olympus (Pragmatic Play)

These games use a “pay anywhere” system – symbols win when enough of them land anywhere on the grid – plus tumbling reels and random multipliers. Both have RTPs of about 96.5% and high volatility, and both are among the most played slots in many casinos.

Immortal Romance (Microgaming)

A dark vampire love story with four different free spins features that unlock as you play more. RTP is around 96.9%. See our Immortal Romance review.

• Fair RTP – 96% or more is a good benchmark.
• Volatility that suits you – low for longer sessions, high for the chance of big wins.
• Interesting features – free spins, multipliers or cascades that keep the game exciting.
• Quality and fairness – games from licensed, tested providers.
• Good on mobile – most modern slots are built for phones first.

Our guide on how to choose a slot explains RTP and volatility in more detail.

Popular slots are available at most licensed casinos, often with free spins offers attached. Before you play, compare sites in our best UK casinos list, try games for free in demo mode and browse all our slot reviews.