Find out the maximum stake - The best payout online slots tend to be those with the highest maximum stake, and in many cases, you need to be betting the maximum to scoop the jackpot.For online slots, an RTP of 95% or higher is favorable. Check the return to player (RTP) percentage - This will tell you what the house edge is on the slot.Play popular titles - Look for games with a decent track record of rewarding five or six-figure prizes, rather than titles offering a huge prize that is only won every year or so.The size of the jackpot - You’ll find the biggest prizes attached to progressive slots, because the more that people play, the faster the jackpot builds.There are a number of factors to keep in mind when you want to find the best payout slots online.