How to choose the best online slots
There is no single best slot: the right game depends on your budget and on how you like a session to feel. What you can compare objectively are the numbers studios publish. This ranking puts those numbers side by side for 3,708 games so you can shortlist slots on facts before you play.
RTP and its versions
RTP is the share of wagered money a slot returns over a very large number of spins. The median headline RTP in the catalogue is 96.14%. The headline figure is the highest version a studio publishes: 737 slots here also come in lower versions that operators can choose, recorded for Hacksaw Gaming, Play'n GO, Push Gaming and Yggdrasil. Each slot page lists every version and what it costs per $1,000 wagered; sort by “Highest lowest recorded RTP” to rank games by their worst case.
Volatility and max win
Volatility is the studio’s label for how unevenly the return arrives: small wins often, or big wins rarely. Max win is the ceiling of a single round as a multiple of the bet. When a studio does not publish one of them, the game shows a dash rather than a guess.
The WildmarkSlots value score
A 0 to 10 indicator built from the headline RTP (70%) and the published max win (30%, on a logarithmic scale). It ranks how generous the numbers are, not how fun a game is, and the same formula applies to every studio. See the formula and a worked example.
Features
Bonus buy, Megaways, cascading reels, free spins and the win system (paylines, ways or cluster pays) are recorded from studio rules for 309 games so far. Use the Features filter to narrow the list, or read how slot features work.
Where the data comes from
RTP, volatility, max win and release year come from the Slot RTP Database by toolsgambling.com (CC BY 4.0), which links every row to the studio’s own page; this snapshot was taken on 2026-09-28. Mechanics come from an open dataset read from studio rules (MIT).