Online slots are virtual versions of the classic slot machines found in brick-and-mortar casinos and come in a variety of themes and game types. They feature reels that spin and randomly come to a stop thanks to a random number generator (RNG), which is regularly audited to ensure fairness. Players win money by lining up matching symbols on what are called paylines, which run horizontally across the reels. Some online slot games allow players to select how many paylines they want to include in their spins, and the more paylines included, the higher the potential for a winning combination.

In addition to the usual slot symbols, some online slot games also feature special icons known as wilds and scatters. These symbols can award payouts regardless of their position on the reels, and some of them can trigger bonus rounds. Moreover, they can sometimes be used to unlock different gameplay modes such as free spins or multipliers.

There are a lot of different bonus features that can be triggered in online slot games, and each developer offers its own variation on this theme. These extras are meant to add more excitement to the gameplay and increase your chances of winning. For example, one common bonus feature is known as tumbling or cascading symbols, which drop from above to replace other symbols and create additional wins. This can happen on a single reel, a group of reels, or even an entire row.

Another way to win is by triggering a bonus round, which can be anything from a simple pick-and-click game to a more involved mini-game with a chance to win a progressive jackpot or other prizes. The exact bonus round rules vary from slot to slot, but they often involve picking up or grabbing objects and/or avoiding certain items.

In order to maximize your chances of hitting a bonus round, you should play slots that have a high RTP and low volatility. The RTP is the percentage of the total amount wagered that a slot will return to the player. It does not mean that a particular slot will pay out more or less often than others, but it is a good indicator of how much you can expect to win from each spin.

The best online slot sites offer a wide selection of games from leading software studios, with options for all budgets. They include Megaways, instant wins, and Megaclusters slots, as well as traditional, 3D, and progressive jackpot games. They also offer a variety of volatility levels, so there is something for everyone. Some of the top-rated online casinos also offer a wide range of tournaments that let players compete against other players to win real cash and prizes. This is a great way to test out new strategies without risking any of your own money.