Step-by-Step Guide: How to Choose the Best Online Slot Games

Some slot games deliver steady entertainment with frequent wins, while others focus on massive payouts with higher risk. To make the best choice, players should consider several objective factors, including mathematical design, bonus features, and game providers. Below is a clear, step-by-step guide that explains how to evaluate slots before you play.

Step 1: Check RTP (Return to Player)

Return to Player (RTP) is the single most important metric when comparing slot games. RTP is expressed as a percentage and shows how much a game is programmed to pay back to players over the long term. For example, a slot with a 97% RTP is designed to return $97 for every $100 wagered, calculated across millions of spins.

Why does this matter? Slots with a 96% RTP or higher statistically provide better long-term returns compared to those with a lower RTP. High RTP games such as Book of 99 (99% RTP) or Mega Joker (up to 99%) are widely considered some of the most player-friendly choices.

When choosing a casino to play at, check if it publishes the RTP values for each game. Reputable providers like NetEnt, Relax Gaming, and Playtech often list multiple RTP versions of the same slot. Always ensure you’re playing the highest available RTP variant, as some casinos may host lower settings.

Step 2: Consider Volatility

While RTP tells you the long-term payout percentage, volatility (also called variance) explains how those payouts are distributed. In simple terms, volatility measures the risk and reward pattern of a slot game.

• Low volatility slots pay out smaller prizes frequently. They are ideal for players with limited bankrolls or those who prefer longer gaming sessions with steady returns. Examples include classics like Starburst (NetEnt).
• High volatility slots deliver larger wins but less often. These games appeal to risk-takers chasing big jackpots or bonus round payouts. Popular examples are Book of Dead (Play’n GO) or Gates of Olympus (Pragmatic Play).
• Medium volatility slots strike a balance between the two, offering a mix of moderate payouts and reasonable frequency.

Choosing the right volatility depends on your playing style. If you want entertainment and consistency, low or medium volatility games are best. If you’re aiming for life-changing jackpots or huge multipliers, high volatility slots provide the thrill you’re after.

Many casinos and providers now display volatility levels in game information screens. Use this data to align the slot’s payout pattern with your risk tolerance, budget, and goals, ensuring a smoother overall experience.

Step 3: Look at Bonus Features

Beyond RTP and volatility, the bonus features built into a slot are what often make it stand out. Features influence both the excitement level and the payout potential of a game, giving you more ways to win beyond standard base spins.

Common features to evaluate include:

• Free Spins – Triggered by scatter symbols, free spins rounds often include added multipliers or expanding wilds for bigger payouts.
• Multipliers – Increase the value of your winnings by 2x, 5x, or even more. Popular in high-volatility games like Gates of Olympus.
• Wilds and Sticky Wilds – Substitute for other symbols and can remain locked in place for multiple spins.
• Cascading Reels / Tumble Mechanics – Remove winning combinations and replace them with new symbols, giving multiple wins on a single spin.
• Jackpot Features – Either progressive (shared network prize pools like Mega Moolah) or fixed jackpots.

When choosing the best slot for you, think about whether you want steady feature triggers (like frequent free spins in low-volatility slots) or rare, high-paying mechanics (like progressive jackpots). Always read the game’s paytable to understand how and when these features activate, as they can significantly affect both entertainment value and potential returns.

Step 4: Select Themes & Providers

When comparing the best online slots, it’s important to look beyond payouts and mechanics — the theme and provider play a major role in the overall experience. A well-designed slot that matches your interests will keep you engaged longer, while a reputable provider ensures fairness and quality.

Slot themes range from classic fruit machines to mythology, adventure, fantasy, or branded entertainment. For example, Book of Dead appeals to players who enjoy ancient Egyptian stories, while Guns N’ Roses targets fans of music-themed slots. Choosing a theme that excites you adds immersion and makes long sessions more enjoyable.

Providers determine game quality, payout consistency, and reliability. Trusted slot game developers, such as NetEnt, Microgaming, Pragmatic Play, Relax Gaming, and Play’n GO, are known for publishing their RTP values and undergoing independent testing. Some studios also specialize in certain mechanics — for example, Big Time Gaming with its Megaways engine or Pragmatic Play with multiplier-rich slots.

By combining an engaging theme with a reliable provider, you can enjoy both entertainment and trust. When evaluating slots, always check the developer behind the game and confirm it’s available at a licensed casino for maximum security.

Step 5: Test Free Play Versions

Before committing real money, it’s smart to test slot games in demo mode. Most top providers and casinos allow players to spin their games for free, using virtual credits instead of cash. This lets you experience the gameplay, features, and volatility firsthand without risking your bankroll.

Demo versions help you:

• Understand how often bonus features trigger.
• See whether the volatility matches your expectations.
• Experiment with different betting levels to gauge session length.
• Compare themes and mechanics across multiple games before deciding.

On SlotsRank, players can try demo versions of popular slots directly while reading detailed reviews. Each review outlines the game’s RTP, volatility, features, and provider background, giving you both practical play experience and expert evaluation. This way, you’re not relying on theory alone — you can confirm whether a game suits your style before depositing at a casino.

Testing games in demo mode is one of the most effective ways to avoid disappointment. By combining first-hand experience with SlotsRank reviews, you ensure your final choice is both entertaining and strategically aligned with your goals.

Step 6: Check Betting Limits & Bankroll Fit

Even the most exciting slot won’t be enjoyable if it doesn’t match your budget and playing style. That’s why evaluating betting limits is an important step when choosing the best online slots.

Most modern slots allow wagers ranging from $0.10 to $0.20 per spin, making them accessible even to players with small deposits. A $3 deposit, for example, can provide multiple gaming sessions on low-stake slots. At the other end of the scale, many slots accept bets of $50, $100, or more per spin, catering to high rollers.

When reading SlotsRank reviews, you’ll find information about each game’s minimum and maximum bets. This allows you to determine whether the slot aligns with your bankroll strategy quickly. If you prefer long sessions, opt for low-stake games with steady payouts. If you’re chasing high-volatility wins, ensure your budget can handle long dry runs before big payouts land.

Always plan your deposit size around the game’s betting range. By selecting slots that align with your bankroll, you can play comfortably, avoid overspending, and maximize entertainment while still keeping an eye on potential returns.

Step 7: Analyze Mobile Performance

Today, most players spin the reels on their phones, which makes mobile optimization a critical factor when choosing the best online slots. A well-optimized slot ensures smooth gameplay, fast loading times, and easy navigation across smaller screens, without sacrificing graphics or features.

Leading providers such as NetEnt, Play’n GO, and Pragmatic Play design all their new releases in HTML5, which automatically adapts to different devices and operating systems. This means whether you play on Android, iOS, or tablet, the game will scale seamlessly and maintain the same payout mechanics as the desktop version.

Mobile-optimized slots also retain all bonus features, RTP rates, and volatility settings, ensuring fairness and consistency, regardless of where you play. For players who enjoy fast spins or quick sessions, mobile play provides the convenience of accessing games anytime, anywhere. Read our comprehensive guide on the differences between desktop and mobile slots to understand the pros and cons better.

With thousands of slots available, narrowing down the best games requires looking at specific strengths. Some excel with high RTP, others with unique mechanics, immersive themes, or sheer popularity. To make your choice easier, we’ve ranked the top 10 online slots, each representing the best in its category. Every game has been thoroughly evaluated for its RTP, volatility, bonus features, and overall player experience, allowing you to match your preferences with the right title.

Best High-RTP Overall — Book of 99 (Relax Gaming)

Book of 99 by Relax Gaming is one of the most player-friendly slots ever released, thanks to its exceptional 99% RTP. This figure is far higher than the industry average of 95–96%, giving players a better long-term chance of recovering their wagers. The slot uses a simple 5x3 reel structure with 10 fixed paylines, making it easy to follow while still offering strong payout potential.

This is a high volatility slot, which means wins may be infrequent but can be very rewarding when they land. Players can wager anywhere between $0.10 and $100 per spin, making it accessible to both casual players and high rollers. The maximum payout reaches around 5,000x your bet, with some reviews citing potential wins of over 12,000x during free spins.

What makes Book of 99 unique is its collection mechanic. In addition to triggering free spins with three or more scatter symbols, players can collect 99 book symbols during base gameplay to guarantee entry into the free spins round. Once inside, a random symbol is chosen to expand across reels, creating the possibility for massive payouts.

The slot’s design draws on ancient Greek mythology, with heroic characters and atmospheric graphics. Combined with its sky-high RTP and innovative mechanics, Book of 99 is a standout choice for serious slot players.

Key Features:

• RTP: 99%
• Volatility: High
• Layout: 5 reels, 3 rows, 10 paylines
• Betting range: $0.10 – $100 per spin
• Max win: ~5,000x bet (up to 12,000x reported)
• Free spins triggered by scatters or by collecting 99 symbols
• Expanding special symbol during free spins
• Ancient Greek theme with strong visuals

Best Retro High-RTP — Mega Joker (NetEnt)

Mega Joker by NetEnt is a timeless classic that combines old-school slot design with one of the highest RTPs in the industry. Depending on how you play, the RTP can reach an impressive 99%, far above most modern slots. To unlock this full potential, players must use the Supermeter mode, which is only available when betting at higher coin levels. At lower stakes, the RTP decreases, making maximum settings the best choice for value seekers.

The slot features a 3x3 reel setup with 5 fixed paylines, bringing simplicity to its gameplay. Unlike modern video slots, Mega Joker has no elaborate free spins or cascading reels. Instead, the excitement comes from its Supermeter function and, in some versions, a progressive local jackpot that can deliver big wins.

As a high volatility slot, wins don’t come often, but when they do — especially in Supermeter mode — they can be substantial. Betting starts from as little as $0.10 per spin and goes up to around $10 per spin, making it most appealing to players comfortable with higher risk and traditional gameplay. Mega Joker is the perfect choice for fans of retro slots who also want to maximize their return potential.

Key Features:

• RTP: Up to 99% (highest in Supermeter mode)
• Volatility: High
• Layout: 3 reels, 3 rows, 5 paylines
• Betting range: $0.10 – $10 per spin
• Max win: ~2,000x bet + progressive jackpot (in some versions)
• Supermeter mode boosts RTP and payout potential
• Classic fruit machine theme with retro visuals

Best Low-Volatility High-RTP — Blood Suckers (NetEnt)

Blood Suckers by NetEnt is one of the most popular choices for players who want both high returns and low risk. With a 98% RTP, it ranks among the top-performing online slots in terms of long-term payout potential. Unlike many high-RTP games that come with steep volatility, Blood Suckers offers low volatility gameplay, which means frequent smaller wins — perfect for players with limited bankrolls or those who prefer longer sessions.

The slot is played on a 5x3 reel grid with 25 fixed paylines. Betting starts at $0.25 per spin and goes up to $50, making it suitable for both casual players and more committed bettors. Although the maximum win potential is around 1,000x your bet, the frequency of payouts keeps the experience engaging and reliable.

Blood Suckers stands out with its combination of free spins and an interactive bonus game. Landing three or more scatter symbols triggers a free spins round with a 3x multiplier on all wins, while the "Vampire Slaying Bonus" allows players to pick coffins and stake vampires for instant prizes. This mix of features ensures variety and excitement in every session.

With its atmospheric horror theme, strong RTP, and consistent wins, Blood Suckers remains one of the best low-volatility slots on the market.

Key Features:

• RTP: 98%
• Volatility: Low
• Layout: 5 reels, 3 rows, 25 paylines
• Betting range: $0.25 – $50 per spin
• Max win: ~1,000x bet
• Free spins with 3x multiplier on all wins
• Interactive Vampire Slaying Bonus game
• Dark horror theme with gothic visuals

Best High-RTP Themed — 1429 Uncharted Seas (Thunderkick)

1429 Uncharted Seas by Thunderkick is a beautifully themed, ocean-adventure slot that blends high RTP and low volatility — ideal for players who prefer steadier returns. The officially published RTP is about 98.5-98.6%, putting it among the top high-return games available. It features a standard 5×3 reel layout with 25 fixed paylines. Bets start very low (≈ $0.10 per spin) and go up to about $100 per spin, making it accessible both to casual players and those staking higher amounts.

The slot includes expanding wilds (the Ship symbol) which appear on reels 2, 3, and 4; when part of a winning line, the wild reels expand vertically to cover the full reel, increasing win potential. Free spins are triggered via Bonus (Compass) scatter symbols: 3 scatters grant 10 free spins, 4 grant 20, and 5 grant 50. Free spins can retrigger. Maximum win is around 670× your bet. The ocean map visuals, compass, mythical sea creatures, and calming yet immersive graphics make this not just statistically generous but also artistically rewarding.

Key Features:

• RTP: ~98.5-98.6%
• Volatility: Low
• Layout: 5 reels, 3 rows, 25 paylines
• Betting range: $0.10 – $100 per spin
• Max win: ~670× bet
• Free spins: 10, 20, or 50 depending on scatter symbols
• Expanding wilds feature on reels 2-4 when part of a winning line
• Theme: Nautical / Mythical Seas with immersive visuals

Best High-RTP (Premium Mechanics) — Marching Legions (Relax Gaming)

Marching Legions by Relax Gaming is a standout slot for players seeking high RTP combined with rich, strategic features. It boasts a published RTP of 98.12%, which drops slightly to ~97.13% if using the bonus-buy feature. With high volatility, this slot rewards patience and commitment. The game uses a 5×3 reel layout with 243 ways to win, and you can stake from $0.10 per spin up to $100 per spin, making it accessible to a wide range of players.

Central to Marching Legions are its mechanics: stacked Legionnaire symbols, nudges, respins, and a Collect Meter that tracks symbol stacks marching across reels. When enough are collected (330 stacks in base play), the free spins feature is unlocked. Free spins proceed through waves: starting with stacks on the rightmost reel and advancing with more stacks and challenges, with the possibility of increasingly big wins. The max win is about 10,000× your bet. Bonus buy option costs about 120× stake to skip straight to the free spins mode. Visually, the theme draws on ancient Roman legion imagery, with clean art style and an animated marching effect across reels, combining entertainment with strong payout upside.

Key Features:

• RTP: 98.12% (≈97.13% via bonus buy)
• Volatility: High
• Layout: 5 reels, 3 rows, 243 ways to win
• Betting range: $0.10 – $100 per spin
• Max win potential: ~10,000× stake
• Bonus buy: available (≈120× stake cost) to access free spins directly
• Waves in free spins: free spins proceed through up to 5 waves with increasing stacks of legionnaires
• Collect meter: stacking symbols and "horns" to fill meter levels and move to waves

Most Popular Evergreen — Starburst (NetEnt)

Starburst by NetEnt remains one of the all-time favorite online slots, especially for players who value steady, frequent wins and a clean, colorful interface. It offers an RTP of about 96.09%, along with low volatility, which makes it ideal for long play sessions and casual budget. The game uses a 5×3 reel layout with 10 paylines that pay both ways (left to right and right to left), increasing your chance of hitting combinations.

Betting ranges from $0.10 per spin up to $100 per spin, giving both entry-level players and higher stakes users flexibility. The signature feature is the expanding wild on reels 2, 3, and 4; when wilds appear, they expand to cover the reel and trigger a re-spin (up to three re-spins) if wilds keep landing. There’s no progressive jackpot or large bonus round, but those mechanics are part of its charm — simplicity, regular wins, and visual appeal.

Because of its accessibility, visual polish, and reliable payout structure, Starburst is a strong pick for anyone wanting a classic, no-complexity but still rewarding slot experience.

Key Features:

• RTP: ~96.09%
• Volatility: Low
• Layout: 5 reels, 3 rows, 10 paylines
• Betting range: $0.10 – $100 per spin
• Max win potential: ~50,000 coins; about 500× your stake depending on coin size and casino display
• Signature feature: Expanding wilds on reels 2-4 that lock and trigger re-spins
• Theme: Cosmic / gem-based visuals, gem symbols + BAR and 7 symbols

Best "Book"-Style Crowd-Pleaser — Book of Dead (Play’n GO)

Book of Dead by Play’n GO is a popular slot among players who love "Book" style games, as it combines a compelling theme, high volatility, and big win potential into one cohesive package. The slot has an RTP of 96.21%, placing it just above industry averages. As a high volatility game, Book of Dead pays out less frequently, but when wins happen — especially in the free spins round — they can be very substantial.

It uses a 5×3 reel layout with 10 adjustable paylines. Bets range from as little as $0.01 per spin (coin value minimum) up to $100 per spin, giving both casual players and high rollers flexibility. The maximum payout is up to 5,000× your bet when conditions align.

Key gameplay features include a free spins bonus triggered by landing three or more scatter/wild Book symbols. In the free spins mode, a randomly chosen symbol becomes an expanding symbol, which can cover an entire reel and lead to large wins. The free spins round also allows retriggers when additional scatter symbols land. The theme is Ancient Egypt, focused on exploration and treasure, with immersive visuals and sound that enhance the adventurous feel.

Key Features:

• RTP: 96.21%
• Volatility: High
• Layout: 5 reels, 3 rows, 10 adjustable paylines
• Betting range: $0.01 – $100 per spin
• Max win: ~5,000× bet
• Free spins feature with expanding special symbol
• Scatter/wild Book symbol acts as both wild and free spins trigger
• Retriggers of free spins possible when scatter symbols land during the free spins round
• Ancient Egyptian theme with immersive audio-visuals featuring Rich Wilde & mythic symbols

Best Megaways — Bonanza Megapays (Big Time Gaming)

Bonanza Megapays by Big Time Gaming is the progressive jackpot version of the legendary Bonanza slot. While it retains the same mining theme, cascading reels, and up to 117,649 ways to win from the original Megaways, the big difference is the linked Megapays jackpot system. This allows players to compete for four progressive jackpots — Mini, Midi, Major, and Mega — which can climb to life-changing sums.

The base RTP is approximately 96.40%, although part of this value is allocated to the jackpots. The volatility is high, so payouts can be less frequent, but they are boosted by the possibility of landing massive wins through both standard gameplay and the progressive prizes. Betting ranges from $0.20 per spin up to $20 per spin, suitable for both casual players and higher-risk takers.

Core gameplay remains true to the original: cascading wins ("reactions"), free spins triggered by landing scatters spelling "GOLD," and increasing multipliers in the bonus round. What sets Bonanza Megapays apart is that the jackpot feature can trigger at random on any spin, adding suspense to every round. For players who want the excitement of Megaways gameplay combined with the thrill of chasing jackpots, Bonanza Megapays is the ultimate choice.

Key Features:

• RTP: ~96.40% (varies as jackpots are progressive)
• Volatility: High
• Layout: 6 reels, Megaways engine with up to 117,649 ways
• Betting range: $0.20 – $20 per spin
• Max win potential: ~17,926× bet, plus progressive jackpots
• Four progressive jackpots: Mini, Midi, Major, Mega
• Cascading reels and unlimited win multipliers in free spins
• Theme: Mining / gem mine visuals with immersive soundtrack

Best Multiplier Action — Gates of Olympus (Pragmatic Play)

Gates of Olympus from Pragmatic Play is a mythological, high-volatility slot built for players chasing big multipliers and thrilling gameplay. Its RTP is generally 96.50%, placing it just above average in terms of return, though some casino versions use slightly lower settings. Betting starts at $0.20 per spin and may go up to $100, allowing both cautious and aggressive players to participate.

The game uses a 6×5 grid with a "pay anywhere" style: wins are awarded when at least 8 matching symbols land anywhere, not along fixed paylines. A Tumble feature causes winning symbols to disappear and new ones drop down, potentially triggering multiple wins from a single spin. Free spins are triggered by landing four or more Zeus scatter symbols, awarding 15 free spins. During free spins, random multipliers (from 2× up to 500×) may appear and accumulate, boosting total winnings.

Gates of Olympus doesn’t offer a progressive jackpot, but its real draw is the multiplier action, the immersive graphics, and strong win potential — with the maximum win capped at around 5,000× your stake. For players who enjoy risk, visual spectacle, and feature-driven slots, Gates of Olympus offers a powerful combination.

Key Features:

• RTP: ~96.50% (operator/version dependent)
• Volatility: High
• Layout: 6 reels, 5 rows, pay-anywhere mechanic (8+ matching symbols anywhere)
• Betting range: $0.20 – $100 per spin
• Max win potential: ~5,000× your bet
• Trigger condition for Free Spins: 4+ Zeus scatters
• Multiplier feature: Random multipliers (2× to 500×) that apply during free spins (and sometimes base game)
• Tumble / cascading reels mechanic that allows symbols to drop and chain react for multiple wins from one spin

Best Popular Slot — Big Bass Bonanza (Pragmatic Play)

Big Bass Bonanza by Pragmatic Play is a fan favorite, especially for players who enjoy engaging bonus rounds, high win potential, and a theme that’s light-hearted and fun. The RTP is 96.71%, placing it above average, and it has medium-to-high volatility, meaning wins may not occur frequently, but when they do, they can be quite substantial.

The game runs on a classic 5×3 reel grid with 10 fixed paylines. Betting starts at $0.10 per spin and goes up to $250 per spin, making it accessible for both casual players and big bettors looking for more than just small wins. The maximum payout is about 2,100× your bet, typically achieved through its free spins feature.

One of the key draws is the free spins bonus: trigger it by landing three or more "scatter" symbols (usually the "Big Bass" symbol). In free spins, the fisherman wild symbol collects "fish cash values" from fish symbols, and every fourth wild collected in the bonus round retriggers the feature. Multipliers on fish cash values during free spins can greatly increase returns. The visuals are bright and playful, with a fishing-theme overlay, cartoonish symbols, and a soundtrack that fits the casual-thrill vibe.

Key Features:

• RTP: 96.71%
• Volatility: Medium-High
• Layout: 5 reels, 3 rows, 10 fixed paylines
• Betting range: $0.10 – $250 per spin
• Max win: ~2,100× your stake
• Trigger: Free spins via 3+ scatter symbols
• Bonus: Fisherman wild collects cash fish values; every 4th wild in free spins retriggers round
• Theme: Fishing – fish symbols, fisherman wild, underwater visuals with lighthearted tone

Slot Game	RTP	Volatility	Layout / Paylines	Betting Range	Max Win	Special Features / Notes
Book of 99 (Relax Gaming)	99%	High	5×3, 10 paylines	$0.10 – $100	~5,000× (up to 12,000×)	Free spins from scatters or 99 symbol collection, expanding symbol
Mega Joker (NetEnt)	Up to 99% (Supermeter)	High	3×3, 5 paylines	$0.10 – $10	~2,000× + progressive (in some versions)	Supermeter mode, local progressive jackpot
Blood Suckers (NetEnt)	98%	Low	5×3, 25 paylines	$0.25 – $50	~1,000×	Free spins with 3× multiplier, Vampire Slaying bonus game
1429 Uncharted Seas (Thunderkick)	~98.6%	Low	5×3, 25 paylines	$0.10 – $100	~670×	Expanding wilds on reels 2–4, up to 50 free spins
Marching Legions (Relax Gaming)	98.12% (97.13% bonus buy)	High	5×3, 243 ways	$0.10 – $100	~10,000×	Stacked legionnaires, nudges, respins, waves free spins, bonus buy
Starburst (NetEnt)	~96.09%	Low	5×3, 10 paylines (both ways)	$0.10 – $100	~500× (50,000 coins)	Expanding wilds with up to 3 re-spins, iconic cosmic theme
Book of Dead (Play’n GO)	96.21%	High	5×3, 10 paylines (adjustable)	$0.01 – $100	~5,000×	Free spins with expanding symbol, retriggers possible
Bonanza Megapays (BTG)	~96.40%	High	6 reels, up to 117,649 ways	$0.20 – $20	~17,926× + jackpots	4 progressive jackpots (Mini–Mega), cascading reels, free spins multipliers
Gates of Olympus (Pragmatic Play)	~96.50%	High	6×5 grid, pay-anywhere (8+)	$0.20 – $100	~5,000×	Tumble reels, random multipliers up to 500×, free spins
Big Bass Bonanza (Pragmatic Play)	96.71%	Medium–High	5×3, 10 paylines	$0.10 – $250	~2,100×	Free spins with fisherman wild collecting cash fish, retriggers with multipliers