How do I use the Monitor & Display Calculators - Test Before You Buy?

Click Start Test (or the equivalent button) to begin. The test runs directly in your browser — no software installation required. For best results, close other apps to free up GPU resources, and run the test in full-screen mode (F11 in most browsers). Results appear within seconds and can be screenshot for documentation or warranty claims.

What does the Monitor & Display Calculators - Test Before You Buy test for?

This tool tests the specific display characteristic described above using standardized test patterns that reveal issues your eyes might miss during casual use. The patterns are designed to stress-test the panel in ways that surface manufacturing defects and performance limitations that matter for real-world use.

Is the Monitor & Display Calculators - Test Before You Buy free to use?

Yes — all TestBeforeYouBuy test tools are completely free, no account required. We believe you should be able to verify your purchase before or after buying without paying for the tools to do so. If you find a defect using our tools, our troubleshooting guides and return policy guides help you take the next steps.

Monitor & Display Calculators

Professional calculators to help you choose the perfect monitor or display for your needs.

PPI Calculator

Calculate pixels per inch for any display resolution and size

Viewing Distance Calculator

Find the optimal viewing distance for your monitor size

Aspect Ratio Calculator

Calculate and compare different aspect ratios

Refresh Rate Calculator

Calculate frame times and refresh rates

Monitor Value Calculator

Calculate your monitor's current resale value

Cost Per Use Calculator

Is it worth buying? Get your true cost per use and a straight verdict

What to test, and what to replace it with

These tools exist to tell you whether a screen is worth keeping. If it is not, these are the panels worth running the same tests on instead.

LG C4 65 in OLED evo

The panel most of these test patterns are written against. OLED is where the dead-pixel and uniformity tests actually matter.

Check price on Amazon →

Samsung S90F 65 in OLED

The main alternative to the C4 at the same size, and the one worth running the same tests on before you keep it.

Check price on Amazon →

Calibrite Display Pro HL Colorimeter

Test patterns tell you something is wrong. A colorimeter tells you by how much, and fixes it.

Check price on Amazon →

Dell UltraSharp U2722D

The safe QHD desk monitor when a test turns up a panel you do not want to keep.

Check price on Amazon →

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