Slot machines are the most profitable part of a U.S. casino. From Las Vegas to Atlantic City, slot machines dominate the gaming space. In the US online gambling market, online and mobile slots works the same way. If an online casino features 300 games, 250 of those games will be real money online slots. The wide variety allows for a full range of themes, features, jackpots, and RTPs.

Real money mobile casinos are the same, with Android or iPhone slots dominating the game selection. Read our guide to online slots for real money to learn about slot games, the casinos that feature them, and how we rate real money slots.

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Guide to Online Slots

Our guide to online slots covers the biggest slot designers: Microgaming, RTG and NetEnt. Because land-based slot designers like IGT and Bally slot machines also design online slots, we cover those companies, too. Our guide discusses how slots work, the best and newest online casinos for US players, tips for having fun while playing online slots, and US gambling enforcement.

If you have any questions, feel free to send us an email or read our slots FAQ page, which answers over 120 questions about the online and mobile slots industry in 2021.

Online Slots Real Money Odds

Slot players should know the odds when they play slots online. Learn concepts like variance and the house edge, along with other tips for picking the best online slots.

Top 5 Online Slot Software Developers

Online slots feature more variety than any other game. Most casinos offer Vegas-style online slots with spectacular graphics. Some slot developers focus on huge jackpots, while others rely on bonus games, multipliers, and free spins.

Below are five slot companies players should know about. In the table below, we list each company’s regional focus and their main claim to fame. Follow the links provided to see a more detailed profile of the online slot companies.

5 Online Slot Designers Players Should Know

Slots Provider Online Slots Land-Based Slots Short Profile

IGT Slots

International Global Progressive Jackpots (MegaBucks, Wheel of Fortune), Licensed Slots

Aristocrat Slots

International Australia, North America Famous Slots like 50 Lions and Lightning Link)

RTG Slots

United States No Fun Themes, Reel-Series Slots, Random Progressives

Bally Slots

International North America Licensed Slots, U-Spin Feature, Super Wheel Feature

WMS Slots

International North America Icon Games (Black Knight, Jackpot Party), Licensed Slots (Wizard of Oz, Monopoly)

How We Review Online Slots

Our reviewers rate all slot machine aspects: themes, graphics, paylines, features, and bonus games. In order to be top-notch, real money online slot reviews also should describe a game’s coin denominations, payouts, and jackpots. Here’s a checklist of factors we include in our slot reviews.

  • Graphics and Sounds
  • Theme
  • Gameplay
  • Free or Real Money Slots?
  • Developer
  • Reels & Paylines
  • Bonus Features
  • Jackpot
  • Return to Player (RTP)
  • Overall Rating

Graphics and Sounds

Graphics make games more entertaining and pleasant to play. Sounds enhance the graphics with sound effects, music, and soundbites. Slot designers like Net Entertainment are known for their cinematic graphics.

Theme

Almost all slot games have a theme like the Old West, Ancient Egypt, or Chinese mythology. Other common themes are Las Vegas gambling, exotic tourist spots, various sports, Greek and Norse mythology, superspies, superheroes, and time periods are common, as well. Licensed slots take their theme from a pop culture franchise, including tv shows, movies, comic book characters, and pop music acts.

Gameplay

Software support and gameplay are important, too. Are the controls easy to use? Do the animations load quickly and seamlessly? Is it a free online slot or a real money slot? Both?

Reels and Paylines

Slot machines usually have 3 reels or 5 reels, though 6-reel and 7-reel slots exist. Extra reels sometimes appear in bonus games, often as a Big Reel. Paylines determine the winning combinations on a slot. Some slots don’t have paylines, but have winning combinations: “243 ways to win” and “1056 ways to win” are examples.

Developers

Some players seek out specific designers in the online gambling scene. IGT, NetEnt, Microgaming, and RTG are known for good graphics, big jackpots, or many features, so knowing the design house helps players find the type of slots they like.

Bonus Features

Bonus features enhance a slot title’s gameplay. Popular features include wild symbols, scatter symbols, free spins, bonus games, and multipliers.

Wild Symbols

Wild symbols complete winning combinations, increasing a player’s odds. Online slot games have several types of wild symbols: stacked wilds, expanding wilds, sticky wilds, and cascading wilds.

Scatter Symbols and Free Spins

Scatter symbols unlock free spins, bonus games, or multipliers. Free spins and bonus games give players the change to win cash without risk.

Multipliers

Multipliers increase a slot jackpot’s prize money anywhere between 2x or 100x the normal prize.

Slots Features: The Bonus Wheel and Gamble Features

The bonus wheel feature presents a wide range of prizes in a spinning wheel bonus game. The gamble feature is a double-or-nothing bet on a jackpot you just won.

Fixed Jackpots

Nothing draws players to a slot machine more than its jackpot. 3-reel slots have smaller jackpots, but the hit more often. 5-reel slots have bigger jackpots and more winning combinations.

Progressive Jackpots

Progressive slots like IGT’s Wheel of Fortune and MegaBucks are among the most popular games in the casino world. Online progressive slots like Mega Moolah are sought by online and mobile players. As a general rule, the higher the jackpot, the lower the return-to-player.

Return to Player

Some slot players seek out games with a high return-to-player (RTP). This is the theoretical amount you can expect to have paid back in prize money. A game with a 97% RTP means you’ll win back $97 of every $100 you wager.

Just like blackjack and roulette, players want to know the RTP of a game, so we make that a part of our rating – when published. Players should keep in mind that the RTP on some online slots varies from casino to casino.

 

Highest Payout Rates in Online Slots

Online Slot Designer Return to Player (RTP) Best Features
Ugga Bugga Playtech 99.07% Wild Symbol
Mega Joker NetEnt 99.00% Progressive Jackpot
Jackpot 6000 NetEnt 98.86% 6000-Coin Jackpot
Sweet Sixteen RTG 98.10% 243 Ways to Win, Multipliers
Blood Suckers NetEnt 98.00% Free Spins, Bonus Game
Jack Hammer II NetEnt 97.10% Free Spins
Avalon II Microgaming 97.00% Free Spins, Rolling Reels, Trailing Wilds
Guns ‘n’ Roses NetEnt 96.98% Free Spins, Respins, Wilds, Multipliers
Thunderstruck II Microgaming 96.65% 243 Ways to Win
Wheel of Fortune IGT 96.60% Wheel of Fortune Bonus, Mini Wheel, Wild Bonus

How to Find the Best Mobile Slots Casinos

Most online slot games are now available for mobile play. Our mobile slots guide outlines where you can play for free as well as for real money. We focus mainly on Android slots apps, as well as iOS slots for iPhone and iPad, since mobile casinos always support both. Here’s how to install mobile slots casino apps or find their equivalent.

  1. Visit the online casino’s homepage, then click on the “Mobile” link in the top menu.
  2. Once on the mobile casino page, click on the Android or iPhone icon, depending on your smartphone or tablet’s operating system. Follow the instructions or scan the QR code to download the mobile app.
  3. If you can’t find a mobile page or a mobile slots app, the casino may not require a download. In that case, click on a slot title’s icon. The mobile slot will load in the web browser without a download.
  4. Players with BlackBerry, Windows Phone, or Symbian devices should choose mobile casinos whose games open in the web browser.

How to Play Slots

Now that you’ve chosen an online slot to play, you’ll want to know how to get started. If you’re never played online slots, here’s a step-by-step guide to playing slots for real money.

  1. Join an Online Casino: Register for a player account, then make a deposit using your favorite payment method. Accept the welcome bonus and play slots to clear the requirement.
  2. Pick a Slots Game: Next, click on “Slots” at the games menu at the top of the screen. Choose the slot title with the theme or features that stands out to you.
  3. Choose Paylines: Pick max paylines to activate the biggest jackpot. Most slots require the max lines for the max prize.
  4. Make a Slots Bet: Once the slots screen appears, find the bet options at the bottom of the screen. Click plus (+) or minus (-) to increase or decrease the bet. Choose a safe and fun bet level.
  5. Hit Spin: Keep in mind the overall bet is the coin denomination times paylines. Once you have the right bet level, hit spin for gameplay.
  6. Cash Out Winnings: Continue the same process until you time of the slots session or your bankroll is gone. If you hit the jackpot or have big winnings, cash out your prize money.

Online Slot Tips

Slots don’t require strategy – something that many players prefer. The slot tips below keep that in mind, while also helping players have the best gaming experience possible.

5 Reel Slots

Higher Denominations Equal Better RTP

High rollers get better odds. The higher the return-to-player (RTP), the more you’ll win over a long period of time. This is more a tip for Las Vegas slots, but it also applies to online and mobile slots.

High rollers get better odds. The higher the return-to-player (RTP), the more you’ll win over a long period of time. This is more a tip for Las Vegas slots, but it also applies to online and mobile slots.

Welcome Bonus

Bet Max Paylines to Activate the Main Jackpot

A player must make the max bet (max paylines) for a slot’s biggest jackpot to be active. This isn’t always the case, so read the rules to make sure. Progressive slots always have this rule.

A player must make the max bet (max paylines) for a slot’s biggest jackpot to be active. This isn’t always the case, so read the rules to make sure. Progressive slots always have this rule.

Cashback

Play Within Your Budget

Play for fun and don’t expect to win big jackpots. Slot betting is entertainment, so treat them as an expense – like tickets to a sporting event or concert. Have a slots budget and don’t exceed that amount. Play free online slots if you don’t have the cash.

Play for fun and don’t expect to win big jackpots. Slot betting is entertainment, so treat them as an expense – like tickets to a sporting event or concert. Have a slots budget and don’t exceed that amount. Play free online slots if you don’t have the cash.

No-Deposit Bonus

Accept the Slots Bonuses

Casino sites offer welcome bonuses for new depositors. A bonus offers free cash that can turn into real winnings. Most of these bonuses allow slots to contribute 100% to the wagering requirement, so they’re also slots bonuses. Reload bonuses and weekly bonuses work the same way. Some casinos offer free spin bonuses for selected online slot games.

Casino sites offer welcome bonuses for new depositors. A bonus offers free cash that can turn into real winnings. Most of these bonuses allow slots to contribute 100% to the wagering requirement, so they’re also slots bonuses. Reload bonuses and weekly bonuses work the same way. Some casinos offer free spin bonuses for selected online slot games.

Risk Free Bets

Choose Flat-Top or Progressive Slots

Fixed jackpot slots usually has better odds than progressive jackpots. Their winning combinations hit more often than on progressives slots. On the other hand, progressive slots have lottery-style jackpots.

Fixed jackpot slots usually has better odds than progressive jackpots. Their winning combinations hit more often than on progressives slots. On the other hand, progressive slots have lottery-style jackpots.

Fun Themes

Choose Fun Themes

If you plan long slot sessions, pick interesting themes with graphics and sounds you like, which make the game to be entertaining.

If you plan long slot sessions, pick interesting themes with graphics and sounds you like, which make the game to be entertaining.

Video Poker

Research Online Slots

Read online slot reviews to find the games with the jackpot types, RTP, and features you like.

Read online slot reviews to find the games with the jackpot types, RTP, and features you like.

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