ScreenTestPro Tools

Free Online Monitor Tests

Eight browser-based tests for desktop monitors, laptops, TVs and phone screens. Open any test to start immediately on the first screen—no installation, no account, and no data uploaded.

All 8 monitor tests

Dead Pixel Test

Cycle solid fullscreen colors to spot dead and stuck pixels, then mark them for a warranty claim.

Input Lag Test

Compare click-to-screen latency between settings, or measure true display lag with a camera timer.

Refresh Rate Test

Measure your real Hz, frame-time stability and dropped frames, and check for frame skipping.

Response Time & Ghosting Test

Watch moving targets at different speeds to spot ghosting, smearing and overdrive overshoot.

Backlight Bleed & IPS Glow Test

Fullscreen black and dark-grey screens to check bleed, IPS glow and clouding before the return window ends.

Monitor Color Test

Check gradients, black and white levels, gamma and uniformity to catch crushed blacks and banding.

Text Clarity Test

Find out why text looks blurry: scaling, non-native resolution, ClearType or OLED subpixels.

Viewing Angle Test

See how colors and contrast shift off-axis, and estimate whether your panel is IPS, VA or TN.

What do you want to check?

New monitor unboxing check

Do these three while you are still inside the retailer's 14–30 day return window:

  1. Dead Pixel Test — check all solid colors for dead or stuck subpixels
  2. Backlight Bleed Test — check in a dark room for corner bleed vs IPS glow
  3. Monitor Color Test — verify black level, white saturation and gradient banding

Gaming & motion check

When motion looks blurry, choppy or unresponsive:

  1. Refresh Rate Test — confirm your OS and cable actually deliver full Hz
  2. Response Time & Ghosting Test — tune your monitor's overdrive without overshoot
  3. Input Lag Test — compare Game Mode, V-Sync and VRR settings

Office & sharpness check

When text looks fuzzy or colors shift across the screen:

  1. Text Clarity Test — check OS scaling, 1:1 pixel mapping and OLED/BGR subpixels
  2. Viewing Angle Test — check off-axis gamma and color shift
  3. Monitor Color Test — check RGB Full vs Limited range
Advertisement

New monitor inspection checklist (15 minutes)

Before throwing away the box or peeling off the protective film on the stand, spend 15 minutes running through a structured check. Most retailers accept no-questions returns for the first 14 to 30 days, while manufacturer warranties often require three to five dead subpixels before they approve an exchange.

  1. Let the panel warm up for 15 minutes and wipe dust off with a dry microfiber cloth. Dust specks look identical to dead pixels on a white screen.
  2. Verify resolution and refresh rate first. Open the refresh rate test and text clarity test to make sure Windows or macOS is outputting native resolution at the panel's rated Hz.
  3. Inspect pixels on five solid backgrounds. Use the dead pixel test on black, white, red, green and blue. Mark any suspicious spot so you can photograph it with pixel coordinates for an RMA.
  4. Check dark-room uniformity at realistic brightness. Drop monitor brightness to your normal working level (roughly 30–50% in a dim room) and open the backlight bleed test. Tilt your head side to side: corners that shift with viewing angle are normal IPS glow, while bright spots fixed to the bezel are true bleed.
  5. Check tonal range and motion. Run the monitor color test to make sure black steps 1–4 aren't crushed by a Limited RGB setting, then run the response time test to pick the cleanest overdrive mode.