Best Online Slots UK: 7 Top Slot Sites in UK for Winning Real Money

(Ad) If you're looking for the best online slots in the U.K., you're in luck. We've reviewed the top slot sites and online casinos in the U.K. offering the highest RTPs and best bonuses.

Each of the online slot sites below was evaluated on a variety of factors, including game selection, RTP, jackpots, banking options, bonuses, and reputation.

Whether you're looking for classic slot games, progressive jackpots, or other casino games, you'll find it on our list of the best U.K. slot sites below.

The Best Online Slot Sites in the UK

• MagicRed Casino: Best UK online casino site overall
• Mansion Casino: Best for big wins
• PlayOJO: Best UK online casino with high payouts
• Casino.com: Best gaming software
• SlotsHeaven: Best UK casino site for PayPal
• Grosvenor Casino: Best selection of real money slot games
• RedKings: Best bonuses and promotions

#1. MagicRed Casino: Best Online Slots Overall

MagicRed Casino is the best UK online casino for players who want a variety of slot games from which to choose, as well as a shot at free spins and other welcome bonus benefits. Classic slot games, jackpot games, and branded casino games make up the catalog of online casino games players can enjoy on the MagicRed online slot site.

MagicRed currently provides a welcome bonus for the popular slot game Starburst, as well as occasional bonus spins for special offers. Players in live casino games can get cashback on Saturdays and Sundays as a deposit bonus with no wagering requirements.

The MagicRed U.K. casino site features a secure transaction platform owned by Aspire Global International, LTD. Users can play slot games on their computer or with the MagicRed Casino app. The interface is easy to use on both desktop and mobile versions, and customer support is available from 8:00 am to 00:00 am CET.

MagicRed Casino provides several popular slot games, including:

• Prism of Gems, with a 96.24% RTP and up to 343x multipliers
• Book of Dead, with a 96.21% RTP
• Dragon Lord, with a 96.5% RTP
• Tower of Fortuna, with a 96.09% RTP and 18.15% hit rate

This UK online casino has an assortment of live casino games, including the popular Starburst, Big Bass Bonanza, Rise of Olympus, and more.

MagicRed Casino features a VIP program with seven levels to ascend for awesome benefits, including bonus spins for your birthday and weekly free spins on Sundays. You can also redeem reward points on a sliding scale as you climb the VIP loyalty levels.

Overall, MagicRed Casino is one of the best casino sites in the U.K. for online slot and jackpot games, as well as live dealer games.

Pros:

• One of the highest rated UK online casinos for slots
• Live dealer games
• User-friendly interface
• Over 1000 casino games
• Welcome bonus of 100% up to £25, plus 25 free spins on Starburst
• Secure platform by Aspire Global International, LTD.
• Popular games from Play'n Go, Evolution Gaming, NetEnt, Pariplay, and more
• VIP Program

Cons:

• Doesn't allow instant withdrawal, instead offering "fast withdrawal"
• Customer support isn't open 24/7
• Doesn’t allow players from the United States

Join MagicRed Casino Today and Get a Welcome Bonus Up To $200 + 100 Free Spins

#2. Mansion Casino: Best for Big Wins

Mansion Casino is one of the highest rated UK online casinos, thanks to its impressive selection of games and generous welcome bonus. The brand is one of the longest-running U.K. casino sites available, with highly rated security measures, multiple payment options, an assortment of the most popular online casino games, and live casino games.

The company features a generous standard or high roller welcome bonus. If your first deposit is less than €1000, you can get a 100% extra deposit bonus, limited to the maximum bonus of €500. So if you deposit €250, you'll get a maximum of €500.

If your first deposit is over €1000, you'll get a 50% extra deposit bonus up to the maximum bonus of €5000. So if you deposit €2200, Mansion Casino will give you a deposit bonus of €3300.

Each level of welcome bonus offers includes different wagering requirements. The standard welcome bonus requires users to wager 20 times the deposit and bonus amount before withdrawing, while the high roller bonus only requires 15 times the deposit and bonus before withdrawing.

Mansion Casino allows U.K. players the opportunity to play some of the top slot games available across the best online casino sites, including:

• Ocean Hunter, with a 95.99% RTP
• Age of the Gods: God of Storms, with a 95.15% RTP
• Fire Blaze: Pharaoh's Daughter, with a 96.5% RTP

Players over 18 years of age can also play live jackpot slots, classic slot games, and video bingo games. Like most U.K. online casino sites, Mansion Casino gives loyalty points to reward users with opportunities for bonus wins and higher cash payouts.

Mansion Casino encourages responsible gambling in accordance with U.K. Gambling Commission guidelines. It is one of the best online casino sites in the U.K. for tournaments and live casino games. It also carries several titles with progressive jackpots, like the popular Age of the Gods Roulette game.

Pros:

• One of the most popular casino sites in the UK
• Live dealer games for UK players
• Over 300 British casino games
• Welcome bonus with first deposit bonuses
• Popular games from NetEnt, Playtech, Microgaming, and other major online slot casino game developers
• 24/7 customer support
• Loyalty points system

Cons:

• Doesn't enable instant withdrawal
• Doesn’t allow players from the United States or outside of the United Kingdom

Join Mansion Casino Today and Receive a 100% Welcome Bonus up to $200

#3. PlayOJO: Highest RTP Slots for UK Players

PlayOJO is one of the best UK casino sites for online slots without wagering requirements. The welcome bonus includes 50 free spins on your first deposit toward the popular game, Book of Dead.

PlayOJO has one of the most extensive libraries of online gambling and jackpot games of any U.K. online casino site. Game categories include slot games, roulette, blackjack, card games, live casino games, jackpot slots, game shows, and bingo games. The company includes games from several renowned developers, including Thunderkick, Play'n Go, Yggdrasil, Nyx, and NetEnt.

This U.K. online casino site gives users a chance at bonus spins, the Prize Twister, individual kicker bonuses, and more. For bingo lovers, PlayOJO has a separate Bingo Welcome Package for new users. New U.K. players may only redeem one welcome bonus for the online slots or bingo games.

PlayOJO presents players with several options for progressive jackpot slots, including Mega Moolah, Fishin' Frenzy, Wolf Run, Eye of Horus, and Cleopatra. As one of the most popular gambling sites in the U.K., its expansive online casino includes many of the top titles for online casino slots, such as:

• Sweet Bonanza, with an RTP of 96.48%
• Blue Wizard, with a 96.5% RTP and low-medium volatility
• Wild Swarm, with a 97.03% RTP

PlayOJO free spins have no wagering requirements. You can access your winnings immediately without meeting a minimum wager amount first. As one of the best gambling sites in the U.K., PlayOJO defines a Fair Play Policy in its guidelines and reward policy in agreement with the U.K. Gambling Commission.

Take PlayOJO with you anywhere with their iOS and Android apps to access one of the best U.K. casinos on your mobile device (within legal means). PlayOJO also includes an invitation-only A-Lister VIP program with a dedicated A-Lister manager, faster withdrawals, increased betting limits, exclusive kicker bonuses, birthday gifts, and more.

Pros:

• An expansive collection of British casino games in several categories
• Rewards that include free spins, the Prize Twister, personalized kicker bonuses, and more
• Popular games from Pragmatic Play, Authentic Gaming, Microgaming, and NetEnt
• Welcome bonus that includes 50 free spins on the popular online casino game Book of Dead
• VIP programs through OJO A-Listers and OJOplus
• No wagering requirements
• One of the fastest cashout times of any U.K. casino site
• 24/7 customer support contact

Cons:

• Some users say that the live chat feature needs updating
• Doesn’t allow players from the United States

Join PlayOJO Today and Get 50 Free Spins on First Deposit

#4. Casino.com: Trusted Casino Site with a Variety of Slot Games

Casino.com is one of the most popular online casino sites in the UK. Casino.com is owned by the Mansion Group, owner of some of the best online gambling sites in the U.K., including Mansion Casino listed above. The welcome bonuses include doubling your first deposit bonus up to €400 and giving users up to 200 free spins on qualifying Age of the Gods slot games.

Users will receive 40 free spins when they sign up, then 20 per day each day for the next eight days (160 free spins) that they log in, for a total of 200 free spins. Casino.com has wagering requirements of 20 times the bonus spins before withdrawing for free spins and wagering requirements of 40 times the deposit amount before withdrawing.

Casino.com also uses game weighting to apply rewards and bonuses. It will only apply free spins and welcome bonuses for customers who make their first deposit using credit cards, debit cards, bank transfers, bank methods, or Visa vouchers.

Casino.com was one of the earliest slot sites to play slots online and is one of the best slot sites for payouts at approximately 97% across all their game offerings. The site features an extensive VIP package for loyal players, including a personal account manager, exclusive promotions and reloads, gifts, higher deposit limits, higher bet limits, and VIP events like football matches, ringside seats at boxing matches, and hospitality packages.

This online casino site includes games from some of the best online casino software developers, including Playtech, NetEnt, Pragmatic Play, iSoftbet, and more. Games include some of the most popular British casino games like:

• Age of the Gods: King of Olympus, with an RTP of 95.98%
• Fire Blaze: Sky Queen, with an RTP of 96.58%
• Ark of Ra, with an RTP of 96.14%

Casino.com provides users 24/7 customer support by phone, chat, or email. They also accept several transaction options, including credit, debit, Visa, Mastercard, e-wallet payments, and bank transfers.

Casinos in the U.K. registered with the U.K. Gambling Commission must offer responsible gambling information and tools. Casino.com gives tips for users to recognise a gambling problem, information about where to seek help, and instructions for using their built-in gambling management tools.

Pros:

• Over 600 games from some of the best slot sites developers
• Bonus spins and other rewards
• Several daily promotions, including Golden Sundays, Two for Tuesdays, and Wild Wednesdays
• Drops & Wins promotion with minimum wagering requirements in select games
• Welcome bonus including 200 free spins on popular Age of the Gods games
• VIP program with VIP and VIP Elite levels

Cons:

• Cashout withdrawals can be slow compared to other online casinos in the U.K.

Join Casino.com Today and Get a 100% Welcome Bonus + 200 Free Spins

#5. SlotsHeaven: Great Bonuses and Big Jackpots

SlotsHeaven is one of the Mansion Group's online casinos with games from Playtech and Quickspin. New users can enjoy a 100% extra bonus on their first deposit up to £/€100 and up to 200 free bonus spins on select Age of the Gods slot games.

SlotsHeaven also features daily specials, including Major Mondays, Thunder Thursdays, and Golden Sundays, with special deals on specific games and bonus spins. Like many online casinos, SlotsHeaven sets a max bonus betting limit to restrict bonus abuse and promote responsible gambling and fair play on winnings from bonus spins.

Despite having only Playtech games, SlotsHeaven lets users choose from some of the top-rated games in the best online casinos in the U.K., including Majestic Gold, Age of the Gods, King of Olympus, and more. Players can enjoy some of the best online casino site games with the highest RTPs, including:

• Kingdoms Rise: Sands of Fury, with an RTP of 96.23%
• Fire Blaze: Golden Macaque, with an RTP of 96.5%
• Tiger Stacks, with an RTP of 96.52%

While SlotsHeaven does not have a VIP program, U.K. players can earn loyalty points to buy cash bonuses. The points redemption levels operate on a sliding scale, and users can wait to redeem their points for higher cash rewards.

Like many of the best online casinos, SlotsHeaven issues both iOS and Android apps for mobile device users to play anywhere on the go. It is the best online casino site for users who want to play a range of games with a high RTP, including table games and slot games. The SlotsHeaven online casino has a 97% RTP on average across all of its game offerings.

Pros:

• Approximately 500 of the top games from online casinos in the U.K.
• Welcome bonus including 200 free spins on popular Age of the Gods games
• Players can win bonus spins and collect loyalty points to redeem for cash bonuses
• Both iOS and Android apps 
• Extensive list of approved payment retailers

Cons:

• Bonus betting limit of £5 on slots and 10% of the bonus on other games
• Games from a single software developer may limit user choice

Join SlotsHeaven Today and Claim a 100% Welcome Bonus + 200 Free Spins

#6. Grosvenor Casino: Most Reputable Slot Site for UK Players

Grosvenor Casino started as a brick-and-mortar casino chain in the 1970s and expanded into a top casino site in the U.K. While gamblers can still visit over 50 physical casino locations at Grosvenor Casinos, U.K. players can also enjoy playing online slots from the comfort of their homes.

Grosvenor Casino features a welcome package bonus of £30 for a qualifying £20 minimum deposit. Players must meet minimum wagering requirements to bet five times the qualifying deposit and bonus before withdrawing winnings.

Because of its reputation and history as a brick-and-mortar casino, Grosvenor Casino is also one of the best online casinos. The brand has games from the top software developers in online gambling games, including NetEnt, Microgaming, Play'n Go, and Pragmatic Play. Some of the most popular games at the Grosvenor Casino site in the U.K. include:

• Gonzo's Quest Megaways, 96% RTP
• (Exclusive) Arctic Empress, 95.12% RTP
• (Exclusive) Buffalo Wild, 94.01% RTP
• (Exclusive) Pirates Free Spins Edition, 93.68% RTP

While many Grosvenor Casino VIP rewards target poker players and players visiting a casino location, online players engaged in live dealer games may receive additional rewards and exclusive opportunities. Grosvenor Casino also provides a loyalty points program and a Black Card VIP experience.

Players can access games from one of the best online casinos with the Grosvenor Casino apps, available on Apple and Android Devices. Grosvenor Casino has an app for each game category, including a poker app, sports app, casino app, and live casino app.

Pros:

• Established brand of physical location casinos
• iOS and Android apps
• Cash bonus welcome package
• Over 240 online slots games, including several exclusive games
• Live dealer games, including blackjack, roulette, game shows, baccarat, and more
• VIP program for online players and in-person casino visits

Cons:

• Customer support isn't 24/7 (only open from 8:00 am-11:59 pm)
• Cashout withdrawals may take longer than other online casinos

Join Grosvenor Today and Receive a $30 Bonus When You Deposit Just $20

* New Customers Only. Min Deposit and Max Bonus apply. Bonus is playable on selected games only. Wagering Requirements apply. T&Cs Apply.

#7. RedKings: Highly Rated Online Casino with Fast Payouts

Launched in 2018, RedKings boasts games from NetEnt, Evolution Gaming, Amaya, NextGen, and more. The company has a generous welcome offer for new players, with up to 100% matching of the first deposit of up to €100, plus 15 free bonus spins on the popular game Wolf Gold from Pragmatic Play.

The wagering requirements to withdraw bonuses are 30 times the original deposit plus the bonus value. If the bonus value exceeds the initial deposit value, the required wager must be at least 60 times the bonus value to withdraw.

RedKings Casino allows three types of wagers for its online casino site in the U.K. Players can make a standard wager, a mixed wager, or a special mixed wager. Special mixed wagering is only available to certain players or during special events.

Although new to the U.K. online casinos scene, RedKings may have the most extensive library of games available at any of the casino sites in the U.K., including:

• Champions of Mithrune, 96.25% RTP with high volatility
• Big Bass Splash, 96.71% RTP with high volatility
• Buffalo King Megaways, 96.52% RTP
• Joker's Jewels, 96.5% RTP

RedKings also provides daily tournaments and a VIP loyalty club. The VIP program features six levels of VIP benefits, ranging from Bronze up to Red Diamond. Players win VIP points based on weighted wagers in the casino. Players who reach the top three levels are VIP executives and receive even more benefits, including a personal account manager, invitations to special events, and faster payouts.

RedKings accepts most common payment types for deposits and withdrawals to player accounts. The online casino also includes several tools for responsible play, including self-imposed timers and limits.

Pros:

• Over 1100 slot games, classic casino table games, jackpot games, and more
• Welcome offer up to €100 plus 15 free spins on Wolf Gold
• 24/7 customer support
• 24-hour Lightning Withdrawals
• Owned by SkillOnNet, owner of PlayOJO

Cons:

• Limited games available on iOS and Android apps

Join RedKings Casino Today and Get a 100% Welcome Bonus + 15 Free Spins

What Are Online Slot Machines?

Online slots are digital games that replicate the thrill of gambling in a brick-and-mortar casino. Major software developers like Pragmatic Play, Play'n Go, Microgaming, NetEnt, Evolution Gaming, Amaya, NextGen, and others develop games that simulate coin slots in actual casinos. They also provide users with an engaging experience with free spins and bonus wins.

Other games include classic slot games, live casino games, jackpot games, and other game types. Each game type provides players with a new experience, including story beats, upgrades, advanced visuals, themes, and more.

Online casinos provide U.K. players with the enjoyment of playing slots from the comfort of their homes on their computers — or on-the-go with mobile apps while out and about.

How We Ranked the Top U.K. Slot Sites

The best casino sites do the following:

• Feature a variety of game choices
• Provide user bonuses for new players and regular players as part of a loyalty or VIP program
• Partner with reputable software developers
• Have a high RTP rating
• Accept several payment methods

See how each of these factors affected our rankings of the best U.K. casino sites.

Slot Game Variety

MagicRed and RedKings Casino each include over 1000 games by some of the best slot site developers in the industry. Mansion Casino is close behind, with over 700 games.

PlayOJO has more than 500 games, largely from developers Microgaming and NetEnt. PlayOJO is the only U.K. casino site on the list that emphasizes its bingo game options. Grosvenor is close behind with over 450 games, including several options for live games.

Casino.com and SlotsHeaven each offer players choices between 300 different games from Playtech.

Welcome Bonuses

All of the online casino sites we listed provide welcome bonuses, including free spins and bonus money with deposit matching. They also have other rewards for new users in their first month playing on their chosen U.K. online casino site.

All six sites except PlayOJO include wagering requirements to withdraw welcome bonuses. However, PlayOJO does not require players to meet a specific wager minimum before withdrawing bonus money from their accounts.

Gaming Software

Some of the best software developers for online slot casino site games include Pragmatic Play, Microgaming, NetEnt, Playtech, Play'n Go, Yggdrasil Gaming, IGT, and Novomatic.

Many of the online slot sites on our list feature games from several third-party developers. 

Casino.com and SlotsHeaven get their games just from Playtech. MagicRed and RedKings Casino each include over 1000 games on their online gambling websites and apps from several software developers.

RTP (Return-to-Player)

Most of the casino sites listed boast an RTP of around 96%, although Mansion Casino has an average RTP of 97.25%, and PlayOJO has an average RTP of 96.92%

Payment Methods

Each of these top slot sites in the U.K. offers numerous payment and payout methods for players so they can fund their fun and cash out their winnings. While they take different payment types, each of the best casino sites has several options.

The primary concern for many players is the speed of the transaction. While RedKings provides a 24-hour Lightning Withdrawal, players must first qualify as a VIP Executive. Some platforms provide a 1-2 day transaction window, while others are as slow as 3-5 days, including PlayOJO, Casino.com, and SlotsHeaven.

Types of Online Slot Games in the U.K.

Several different types of slot games exist that appeal to different players, including branded franchise game tie-ins, table games, live games, and progressive jackpots.

Branded Slots

Branded slot games tie a player into a popular franchise while playing. The online casinos on our list of the best slot sites all offer several top branded slots, including Game of Thrones, Rick and Morty, Family Guy, Baywatch, Wheel of Fortune, and Ghostbusters.

Classic Slots

Classic slots have traditional three-reel spins to line up matching symbols for opportunities to win. These traditional format games are becoming rare as even brick-and-mortar casinos switch to digital display games rather than mechanical spinning reels.

Video Slots

Video slots are screen-based slot games that often feature moving graphics, cutscenes, and animations between spins.

Jackpot Slots

Jackpot slots, also called progressive jackpot slots, are games that accrue a jackpot balance as players bet and lose, contributing to the value of the pot. When a player places a bet and wins, they win the accrued value of the jackpot.

Why Play Slots Online?

Playing online slots is fun and a great way to pass some time while waiting for a bus or trying to tune out a bad date.

All of the best online slot casinos listed are trusted sites, with added layers of encryption and SSL certifications to keep your personal information secure. Players can enjoy hundreds of different games without navigating the confusing walkways of an actual casino.

Playing slot games online also allows users to enjoy the experience of winning from their home computer, tablet, or mobile phone. Whether you want to relax after a long day at work, pass the time on a lunch break, or wait for a ride, playing online lets you make a few spins before refocusing on your task at hand.

Frequently Asked Questions

Do you still have questions about U.K. online casino platforms, online slot games, or casino bonuses? Check out the FAQ below to learn more about online U.K. casinos.

Are online casinos legal in the U.K.?

Yes, U.K. online casinos are legal if licensed and regulated by the U.K. Gambling Commission. However, the U.K. banned free online slots sites, as they pose too great a risk for people with gambling problems. U.K. players must be at least 18 years of age to play online slots.

How do online casino bonuses work in the United Kingdom?

U.K. players may qualify for a deposit bonus, welcome bonus, bonus spins, bonus rounds, bonus money, and other special offers for signing up, playing slots online, and winning. Bonuses may vary based on which online casino platform you use to play slots and which casino games you play.

You may also qualify for special VIP or loyalty casino bonuses depending on which U.K. casino site you sign up for. Some casino VIP programs even invite top players to attend football matches, UFC fights, boxing matches, and special tournaments.

What is slot RTP?

The RTP is the return-to-player ratio for different casino games. Players should look for games that feature a 96% RTP or higher, meaning that for every £100, the slot game returns £96. If you want to potentially maximize your return from online slot sites, look for games with a higher RTP rating.

Some games with high RTPs include:

• Mustang Gold on PlayOJO, 96.5% RTP
• Prism of Gems on Magic Red, 96.24% RTP
• Legacy of the Dead on Grosvenor Casino, 96.58% RTP
• Captain's Treasure on Casino.com, 97% RTP
• Wolf Gold on PlayOJO and Casino.com, 96% RTP

Do any slot sites offer free spins?

Several U.K. online casinos allow free spins, including casino.com, playOJO, Magic Red, Grosvernor Casino, and more. Many online gambling platforms provide free spins as either:

• bonus rounds
• part of their welcome bonus, or 
• weekly or monthly bonus spins to drive traffic to their online casino site

Many online gambling platforms now use "bonus spins" instead of "free spins" to better comply with U.K. Gambling Commission regulations.

Can you play online slot games from a mobile app?

Nearly every online casino has an app to download on your mobile device so you can play slots anywhere on the go. While most issue apps for both iOS and Android, some only have an app on one platform. Casinos with larger game catalogs may reduce their game offerings on their mobile platforms.

Some players may prefer to play in their mobile browsers rather than an app if the app doesn't feature their favorite games. You might want to load your favorite game in both the app and the mobile browser to see which version suits your play style best.

What payment methods do most online casinos accept?

Many online casinos accept PayPal, allowing U.K. players to keep their bank account or debit card information private from their favourite casino sites. Many casino sites in the U.K. also accept alternative payment methods, including:

• Debit cards
• Apple Pay
• Google Pay
• Revolut cards
• Paysafecards
• Trustly
• Neteller
• Bitcoin
• Skrill

Every platform's payment processing time differs, even if they accept the same payment service. Review each slot site for payment types accepted and payout times for each acceptable payment type.

Final Thoughts on UK Slots

Carefully review the information we sourced before you decide to sign up for an online slot game site in the U.K. Consider what types of games you might enjoy — live dealer games, bingo, table games, jackpot slots, or other game styles.

Also, consider welcome bonuses. Would you qualify for a deposit bonus, bonus spins, bonus money, or other bonus? Does the casino offer additional VIP bonuses or a loyalty point program? Compare the different platforms in terms of bonus spins, max bonus betting limit, and other factors.

Look at the software partners and find online reviews of their games. Do you like Playtech games, or do you want options between several top software developers? You may be able to find live play demos on YouTube of a casino's most popular games to see if you like the products from particular developers.

You can search for a game's name and "RTP" online to find a specific game's average win rate and volatility. If you prefer low-volatility games, one of our best online casinos might offer more games with more predictable outcomes than another on the list. Just remember that typically, more risk brings a higher reward.

Does your preferred U.K. casino site accept your primary payment method? Verify that your online slot site accepts your payment form before signing up.

We hope you enjoy exploring the world of playing online slots and jackpot games safely with one of the best slot sites listed above. While MagicRed was our top choice, any of these casinos in the U.K. would lead to hours of fun and entertainment while you make real money winning your favorite games.

Summary of the Top Recommended Slots in the United Kingdom

• MagicRed Casino: Best UK online casino site overall
• Mansion Casino: Best for big wins
• PlayOJO: Best UK online casino with high payouts
• Casino.com: Best gaming software
• SlotsHeaven: Best UK casino site for PayPal
• Grosvenor Casino: Best selection of real money slot games
• RedKings: Best bonuses and promotions

*Gambling involves risk and you must not gamble with funds you can’t afford to lose. It is not a solution to any financial difficulty. Remember, the house always wins! 

If you or a loved one is struggling with a gambling addiction, here are some resources that can help:

https://www.begambleaware.org/

Gamblers Anonymous Hotline: 1-626-960-3500