Online monitor test

Five quick checks: whether you can see shadow and highlight detail, what gamma your screen has, whether gradients band, and whether there are dead pixels. Maximize the window and keep browser zoom at 100%.

Black level

You should be able to tell squares apart from about 2–4 upward. If the first 6–8 merge with the background, shadows are crushed: raise gamma or brightness a little. If the background itself looks grey, the GPU outputs a limited RGB range — see full vs limited RGB.

White level

You should see every square up to 251–253. If the right-hand ones merge into white, highlights are clipped: lower contrast on the monitor or in the driver.

Gamma

Step back or squint: the patch that blends into the striped background shows your screen gamma. The standard is 2.2. If 1.8–2.0 blends best, the picture is brighter than standard; 2.4–2.6 means darker.

Your Windows display scaling is fractional (for example 125%) — the stripes may blur and the gamma test will be less accurate.

Gradients

Transitions should be smooth. Visible steps point to a 6-bit panel, signal compression or overly aggressive contrast and gamma settings.

Dead pixels

Press the button and the screen fills with color. Click or Space for the next color, Esc to exit. On black look for glowing dots; on white and colors, look for dark or off-color dots.

Start fullscreen test

If a test fails

• Grey blacks and dull colors — enable full RGB range and check the 8 causes of washed-out colors.
• Shadows too dark in games — raise gamma, not brightness: see Rust too dark at night or Tarkov gamma.
• Colors look dull on a laptop — saturation on Intel graphics.

Frequently asked questions