Best Sci-Fi Browser Games

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.

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

Old Light is a browser strategy game set across a persistent galaxy shared by every player. Claim star systems, grow your economy, and expand your empire's borders while fleets clash with human rivals and NPCs. No download. Jump in and grow your empire.

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

SpacePimpin is where you go when you feel like your true calling was to sell drugs and sex, and kill for power, pride, money, and revenge. And all that in a SciFi theme? Yes. This is heaven.

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.

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.

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.

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

In Prosperous Universe start your galactic empire by trading on the real-time market exchange with other real players. Build your 1st base from humble beginnings & watch as your business flourishes with complex supply chain strategies. Economics, politics & realism fuel this immersive business MMO.

A cyberpunk text RPG set in a city that remembers everything you do — and never forgives.

Idle Cosmos Economics is a multiplayer strategic business simulator. - 7 upgradable facilities, 6 production tiers, 25+ products. - 100% player-driven exchange market, simulated population supply&demand - Global rankings, chat, tenders, consultant hiring.

Galactic Tycoons is a free multiplayer browser game where you command your own industrial empire. Build bases across the galaxy, master complex production chains, and compete in a persistent, player-driven economy. Specialize, trade, and cooperate with other players.

Nullspire is a multiplayer, text-based RPG set in a grim cyberpunk world fractured by corporate ambition. The Nexatech Corporation's experiments with quantum threading—a technology capable of rewriting reality—have torn open rifts, unleashed anomalies, and ignited global conflict.

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.