Online casinos offer a wide range of slots, with many titles designed to look and work on mobile devices. Powered by HTML5, these games work seamlessly on smartphones, tablets and computers, regardless of operating system. They also offer a variety of special features that enhance the gaming experience. Some of these features include tumbling reels, free spins, jackpots and other special rewards.

One of the most common ways to play slot machines is with bonus games, where players can win free spins or extra spins based on specific symbols. Some of these bonus games test player skill, while others are completely random. These games can be found in the video slot section of most online casino websites.

When it comes to slots online, there are two main categories: three-reel games that mimic the old mechanical machines and five-reel video slots. Both have a wide variety of special features to add to the game play, such as wild symbols and scatters. Some even offer progressive jackpots or bonus games, such as wheel spins or picks bonuses.

While some of these special features may seem obvious, new ones are being added all the time. For example, a recent release from Microgaming and AM1 Studios is a Mexican-themed slot that features up to 117,649 ways to win. The game includes stacked wilds, walking wilds, shifting wilds and multiplier wilds, all of which increase the number of possible winning combinations.

Another popular feature is Hold and Spin, where regular symbols are replaced by money or jackpot awards after three spins. This feature was pioneered by Aristocrat and has been copied by virtually all rival developers. This is a great way to keep your interest up and add more excitement to the game play.

These days, the best way to try out a new slot game is to play it for free, before you deposit any real cash. You can find free slots in most casinos, including US-based sites. All you have to do is find a site that offers the slot you want to try, and use its demo mode to see how it plays on your device.

The newest type of free online slot is the 3D slot, which allows you to see all the action on your screen without having to wear special glasses. The graphics are high-quality and make for a truly immersive experience. This type of slot is a welcome addition to the market and will continue to expand as more online casinos offer it.