Browser horror doesn't have the budget for photorealism, so it uses the cheaper and far more effective tools: sound, darkness and waiting.
Tension beats gore
The scariest stretch of any horror game is the one where nothing is happening. Limited visibility, a noise you can't place, a threat that moves when you're not looking — these do more work than any monster design, and they cost nothing to render.
That's why the genre translates so well to the browser. Take away resources and the good designers lean harder on atmosphere, which is what actually frightens people.
Hiding, running and resource panic
Most browser horror games are built around scarcity: not enough light, not enough places to hide, not enough time. The fear comes from managing those things badly and knowing it — you spent the battery too early, you took the loud route, and now something is between you and the door.
Stealth-based titles add a rhythm to that. Learn the patrol, move on the beat, and the terror becomes a puzzle you're solving under pressure.
Keeping your nerve
Play with headphones if you want the full experience, and without them if you'd rather actually finish. Sound design is doing most of the scaring, and turning it down measurably lowers the difficulty.
When you panic, stop moving. Running blindly is how most horror-game runs end — the pursuer is usually faster, and standing still to think costs less than a wrong turn.
