Know what your display is really showing.
Free browser tools to check a new, used, OLED or gaming monitor in about five minutes — then keep a complete inspection report.
Start with the job
A guided path when you do not know what to test first.
New Monitor
The essential checks to run before your return window closes.
02 / INSPECTIONUsed Monitor
A five-minute checklist for an in-person second-hand purchase.
03 / INSPECTIONOLED Monitor
Focus on the panel behaviors worth checking on an OLED display.
04 / INSPECTIONGaming Monitor
Check the settings and motion behavior behind a smoother gaming display.
Or choose a single tool
Visual patterns and browser measurements, with clear limits.
Screen Test
Check the whole panel with clean full-screen color patterns.
Open tool →Monitor Test
Start with the checks that matter when a monitor is new or second-hand.
Open tool →Dead Pixel Test
Show solid colors and find pixels that remain visibly different.
Open tool →OLED Test
Inspect near-black behavior, uniformity and image retention on an OLED panel.
Open tool →Refresh Rate Test
Estimate active refresh timing from browser animation frames.
Open tool →Ghosting Test
Watch a moving pattern and inspect trailing, smearing or inverse ghosting.
Open tool →Backlight Bleed Test
Use a black field to inspect bright areas around the panel edges.
Open tool →Color Banding Test
Display smooth gradients and look for abrupt steps.
Open tool →Grayscale Test
Inspect shadow detail, highlight detail and smooth grayscale transitions.
Open tool →Resolution Checker
See the active screen, viewport, device pixel ratio and browser display capabilities.
Open tool →Inspect → Understand → Report
Your observations stay in this browser. Export a structured PDF when you are done.
Guides
Short, practical reading before or after you test.
Frequently asked questions
What Display Checkup does, and what it deliberately leaves to you.
Is Display Checkup free to use?
Yes. Every test and guided inspection runs in your browser at no cost, and the PDF report is generated locally.
Can a browser test damage my display?
No. The patterns only change what your screen shows. We never ask you to press on the panel or change hardware for a test.
Does Display Checkup decide whether I should return a monitor?
No. The inspection records your observations and browser estimates. Return decisions depend on the seller's policy, so compare your report with it.
Where is my inspection data stored?
In this browser. The guided inspection and the report read your local session, and nothing is uploaded to a server.
Do I need an account or an app?
No. Open the site, run the checks and download the report. Nothing to install and no sign-in.