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Best Sci-Fi Browser Games

Space empires, cyberpunk cities, and futuristic RPGs - the top free sci-fi browser games playable online.

26 hand-picked games · Ranked by community votes

VoidFleet - gameplay screenshot

#1 · 103 votes

VoidFleet

mmopvpbrowsermultiplayerscifi
VoidFleet cover

Voidfleet is a persistent online space strategy game where every decision shapes your growing empire. Colonize new worlds, develop planetary infrastructure, research advanced technologies, build powerful fleets, and command missions across a galaxy connected by strategic hyperlanes. Trade ships and resources with other players, customize commanders through attributes and doctrines, gather intelligence, coordinate with federations, and compete for influence across an evolving universe. Expansion requires more than raw power travel routes, fleet timing, logistics, diplomacy, and economic

Screenshots

VoidFleet screenshot 2VoidFleet screenshot 3VoidFleet screenshot 4VoidFleet screenshot 5
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HiddenWars - gameplay screenshot

#4 · 35 votes

HiddenWars

strategymmopvppvecrime
HiddenWars cover

HiddenWars is a free browser-based hacking strategy MMO set in a near-future cyberpunk underworld. Build your botnet, scan subnets for soft targets, breach them, and launder the crypto before it traces back. Every op raises your heat — go loud or drop off the grid in ghost mode. Form a cell to raid hardened targets, hunt rivals in PvP, claim bounties, and deface their profile when you win. Persistent world, real odds, real consequences — and secrets that aren't on any map. No download, plays in your browser.

Screenshots

HiddenWars screenshot 2HiddenWars screenshot 3HiddenWars screenshot 4HiddenWars screenshot 5
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Interstellar Empires - gameplay screenshot

#5 · 21 votes

Interstellar Empires

mmopvppvestrategyscifi
Interstellar Empires cover

Interstellar Empires is a browser-based 4X strategy game where you build and expand a planetary base, manage resources, research advanced technologies, and command armies and starships in a persistent sci-fi universe. Humanity has uncovered an ancient portal network left behind by a mysterious civilization, allowing players to explore distant worlds and launch rapid ground assaults by dialing unique portal addresses. Expand your economy, train specialized ground units, build powerful fleets for large-scale space battles, mine rare asteroid resources, scout enemy empires, and compete in regular

Screenshots

Interstellar Empires screenshot 2Interstellar Empires screenshot 3Interstellar Empires screenshot 4
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Moons Web3 - gameplay screenshot

#6 · 3 votes

Moons Web3

text-basedmmopvppvefantasy
Moons Web3 cover

MOONS is a Web3 space strategy game inspired by classic games like OGame, but with its own universe, economy, lore, and gameplay systems. Players build and develop their space empire, manage resources, build fleets, explore the universe, trade, fight other players, and encounter AI-controlled pirates. 🚀 Fleet — Build ships and send them on attacks, transport missions, exploration, and expeditions. 🌌 Explore — Discover new planets, resources, anomalies, secrets, and rare discoveries. ⚔️ Combat — PvP and PvE battles with detailed battle reports and combat animations.

Screenshots

Moons Web3 screenshot 2Moons Web3 screenshot 3
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CozmoGame - gameplay screenshot

#7 · 2 votes

CozmoGame

mmostrategypvppvescifi
CozmoGame cover

CozmoGame is a real-time multiplayer space strategy MMO played entirely in the browser, no download needed. Build mines and factories, research technologies, colonize new worlds and grow an interstellar empire. Send fleets on expeditions, mine asteroids, spy on rivals, hunt pirates and fight deterministic large-scale battles with a full combat simulator to plan them. Join an alliance, coordinate ACS attacks and defences, and climb the highscores. Several universes with different speeds, an active Discord community, and 10 languages supported.

Screenshots

CozmoGame screenshot 2CozmoGame screenshot 3CozmoGame screenshot 4CozmoGame screenshot 5
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Idle Galaxia - gameplay screenshot

#8 · 2 votes

Idle Galaxia

text-basedincrementalrpgbrowserscifi
Idle Galaxia cover

Idle Galaxia is a free browser idle RPG set in deep space. Battle monsters, harvest resources, upgrade gear, trade on the market, and join a clan — all from your browser, with no download required. Fight through escalating mobs for gold, battle XP, platinum, and rare stat drops, or train the four harvest skills — Xeno Tracking, Excavation, Core Mining, and Xenobotany — to gather Xeno, Starstone, Neutronite, and Glowvine. Those materials feed tools, components, and long-term progression.

Screenshots

Idle Galaxia screenshot 2Idle Galaxia screenshot 3
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VOID SECTOR - banner

#9 · 1 votes

VOID SECTOR

pvppvescifibrowsermultiplayer

VOID SECTOR is a free multiplayer space game in your browser, currently in online alpha. Explore sectors, mine resources, equip your ship and fight alongside other pilots in a shared universe. No download; creating an account requires email activation. Available in German and English. A GameGeeeeek project.

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Kolonie Kepler-7 - banner

#11 · 0 votes

Kolonie Kepler-7

strategyidlescifibrowsermultiplayer

Kolonie Kepler-7 is a free German-language space strategy game in your browser. Build colonies, manage resources, research technologies, plan fleets and work with an alliance while competing over star systems. Progress continues offline for up to eight hours. No download and no pay-to-win. Developed by GameGeeeeek using generative AI for code, text, images, music and voices. The game interface and help are in German.

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Strategic Empires - gameplay screenshot

#12 · 0 votes

Strategic Empires

mmoeconomywarscifiidle

Strategic Empires is a tick-based multiplayer space strategy game where you build an interstellar civilization, explore and colonize the galaxy, develop new technologies, manage a living economy, conduct diplomacy and espionage, and command fleets in persistent wars. Games can run for months / years.

Screenshots

Strategic Empires screenshot 2Strategic Empires screenshot 3Strategic Empires screenshot 4
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LifePaths - gameplay screenshot

#13 · 0 votes

LifePaths

text-basedrpgscifieconomyroleplay
LifePaths cover

LifePaths is a narrative life simulator: you're born, and you decide everything: career, money, relationships, health. Every action goes through two checks before it counts: first its plausibility, judged by AI, then a roll of a hundred-sided die, resolved by the game's own engine. It all plays out in a 2076 dystopia, where an algorithmic score (the Civic Index) decides what you're allowed to do.

Screenshots

LifePaths screenshot 2LifePaths screenshot 3LifePaths screenshot 4LifePaths screenshot 5
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Hex TD - gameplay screenshot

#15 · 0 votes

Hex TD

pvestrategyscifibrowsermultiplayer
Hex TD cover

Your planet needs defenders. BrowsergameWithNoName is a cooperative, tick-based tower defense — hundreds of players share one hex-grid world and defend it together against AI-driven invasion waves. Pure PvE. No one fights alone. 🔹 Chain towers across a shared world, starting from your indestructible home tower 🔹 Four tower types to counter the AI commander's strategy 🔹 A fixed cycle: prepare, alert, battle — repeat. together

Screenshots

Hex TD screenshot 2Hex TD screenshot 3Hex TD screenshot 4
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Aleryos - gameplay screenshot

#16 · 0 votes

Aleryos

strategyscifipvppvemmo
Aleryos cover

Aleryos is an online multiplayer space strategy game where you lead an empire across a shared galaxy. Build your economy, explore sectors, colonise worlds, command fleets, spy on rivals and defend your territory. Design custom ship models and fleet compositions that fit your strategy, then use the Pillars of the Monarchs to project armies onto planetary battlefields. Forge alliances with shared technologies, coordinated attacks, diplomacy and events spanning PvP and PvE. Available in 20 languages, playable in your browser.

Screenshots

Aleryos screenshot 2Aleryos screenshot 3
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Stellaforge - gameplay screenshot

#17 · 0 votes

Stellaforge

mmopvppvestrategyscifi
Stellaforge cover

Stellaforge is a dark sci-fi MMO strategy game where interstellar empires clash for dominance. Colonize distant worlds, command devastating fleets, research forbidden technology, and wage relentless wars across the galaxy. Every decision shapes your rise. Every battle leaves its mark among the stars.

Screenshots

Stellaforge screenshot 2Stellaforge screenshot 3
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X-Wars Resurrection - gameplay screenshot

#18 · 0 votes

X-Wars Resurrection

mmostrategyscifiwareconomy
X-Wars Resurrection cover

Build an empire in the browser. X-Wars Resurrection is a deep space strategy MMO - colonies, research, layered industry, modular fleets, and a living star map. Rebuilt by one of the original X-Wars developers. Free to start, then a fair monthly subscription - not pay-to-win. Early alpha. No download

Screenshots

X-Wars Resurrection screenshot 2X-Wars Resurrection screenshot 3X-Wars Resurrection screenshot 4
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Galactic Ascent - banner

#21 · 0 votes

Galactic Ascent

rpgmmopvpstrategyscifi

Galactic Ascent is a browser-based sci-fi strategy game where empires rise and fall in 30-day cycles. Discover planets, build industry, command fleets, scout rivals, trade, form alliances, and fight for a permanent place in the Hall of Ascendancy before the galaxy resets.

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Stardust Exile - gameplay screenshot

#23 · 0 votes

Stardust Exile

mmopvppvestrategyidle
Stardust Exile cover

Stardust Exile is an RTS set in the Milky Way galaxy, containing currently known stars and exoplanets with their real characteristics. The remaining star systems are procedurally generated. The server is persistent and single-shard.

Screenshots

Stardust Exile screenshot 2Stardust Exile screenshot 3Stardust Exile screenshot 4Stardust Exile screenshot 5
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Moron Mayhem - banner

#26 · 0 votes

Moron Mayhem

text-basedroleplaybrowserscifirpg

400 years in the future. A machine built to save humanity scanned history, weighed brilliance, and delivered its verdict: Morons. So, it grabbed the overlooked instead. Now you're awake, broke, and surviving by any means necessary. Grift, train, fight, study. Rise above the mayhem or become it.

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About Best Sci-Fi Browser Games

Sci-fi browser games take players to distant galaxies, dystopian megacities, and post-human futures. This ranked list gathers the best free sci-fi browser MMOs and RPGs currently active. All online, all multiplayer, all in your browser.

Looking for other categories? Browse text-based browser games, mafia browser games, crime browser games, browser rpg games, browser mmos, pvp browser games, pve browser games, strategy browser games.