Battle SWAT vs Mercenary Zombie Survival is a free online browser shooter that puts two rival factions head-to-head while zombies crash every engagement. Pick your side – disciplined SWAT or scrappy Mercenary – customize your loadout, and fight through tight maps built around chokepoints, vertical sightlines, and corner-clearing pressure that rewards smart movement over spray-and-pray.

The game runs two distinct modes: PvP skirmishes where human players go at each other, and wave-based zombie survival where you hold positions, burn through ammo, and spend earned cash on better weapons between rounds. TTK is clean and headshots matter, so burst-firing at range and pre-aiming doors will take you a lot further than hipfiring blindly. Clutch teammate revives and map control are what separate good runs from getting wiped in round four. Built in WebGL and Unity, it loads fast and plays smoothly directly in your browser.

If you enjoy free online FPS games, zombie survival shooters, or browser-based multiplayer gunfights with no download required, this one punches well above its weight. It fits perfectly for fans searching for SWAT shooting games online, free zombie wave survival FPS, or browser multiplayer shooters with weapon unlocks. Quick rounds mean you can squeeze in a full match on a short break, and the faction variety keeps repeat sessions feeling fresh.