My screen feels less responsive since fitting a protector
Turn on the phone's touch-sensitivity setting, which exists for exactly this. If it persists, check for trapped air pockets, dead zones are usually bad contact, not the protector's thickness.
Reduced responsiveness after fitting a protector is usually fixable in a settings menu, and where it isn't, the cause is almost always contact instead of thickness.
Try the setting first
Most phones include a setting that raises the capacitive threshold to compensate for an extra layer. It's variously called increase touch sensitivity, glove mode, screen protector mode or high touch sensitivity, and it sits under Display or Accessibility depending on the manufacturer.
This exists precisely for this situation and resolves the majority of complaints. Turn it on before concluding anything about the protector.
Dead zones are a contact problem, not a sensitivity problem
If some areas of the screen respond and others don't, sensitivity isn't the issue. Hold the screen at a low angle against a bright light and look for faint bubbles, a halo, or any region where the protector isn't fully seated.
A capacitive touchscreen senses the change in an electric field caused by your finger. Where a protector is held fractionally off the glass by trapped air or a dust particle, that gap weakens the coupling and the region behaves as a dead zone.
The fix is to reseat the protector — lift the nearest corner with tape, remove whatever is holding it off, and lay it back down.
When thickness genuinely is the cause
Very thick protectors do degrade touch response. Heavy-duty anti-shock designs above roughly 0.5mm can add perceptible latency and reduce sensitivity to light touches.
If you deliberately bought maximum protection, this is the trade you made, and it's a real one. Anything between about 0.25mm and 0.4mm is normal and shouldn't be noticeable.
Edge gestures are a separate problem
A protector with a thick or raised edge can interfere with swipe-from-edge navigation. This feels like unresponsiveness but is geometric: your finger is starting its swipe on top of the protector edge rather than at the screen boundary.
Case-friendly protectors, which stop short of the edge, usually make this worse not better because the ledge sits further inboard. A thinner protector with a properly bevelled edge is the fix.
Things that aren't the protector
Wet or greasy fingers reduce responsiveness on any screen. So does a cracked display beneath the protector, and so do some third-party replacement panels.
If responsiveness was already imperfect before fitting, the protector isn't the cause and removing it won't help.
Common mistakes
Above about 0.5mm you start trading touch response for protection. For gaming in particular that's a bad trade.
It's buried under Display or Accessibility depending on the phone, and is often called glove mode or screen protector mode not anything obvious.
Related questions
How do I fit a screen protector without bubbles?
Fit it in a steamy bathroom after the shower to settle dust, clean with the alcohol wipe then the dry cloth, lift dust with the sticker, align with the frame, and drop it from the middle so the adhesive rolls outwards.
My fingerprint sensor stopped working after fitting a protector. What now?
Re-register your fingerprints with the protector already fitted. That fixes the majority of cases. If it still fails, the protector is too thick or too heavily tinted for the sensor and needs replacing with one rated for in-display readers.
How do I get dust out from under a fitted screen protector?
Lift the affected corner with a strip of sticky tape, use a second piece of tape to lift the particle off the display, then lower the protector back down. Don't slide it — lift it.