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White Screen
Fills your entire screen with solid white. Cleaning the screen, spotting dust and dark…
Green Screen
Fills your entire screen with solid green. Checking green sub-pixels — the channel the eye is most sensitive to, so faults show up here first.
Screen Tests
Nothing uploaded
No sign-up
Free, unlimited
Press Fullscreen, then look closely at the whole panel.
In short
A full green screen matters more than the other two primaries because of how human vision works. The eye has far more sensitivity to green than to red or blue — green carries roughly three quarters of what we perceive as brightness — which means a fault in the green channel is the one you are most likely to actually notice, and the one that shows up here first. A pixel with a dead green sub-pixel appears as a dark dot against the green field while looking almost normal in mixed content. That sensitivity is also why camera sensors have twice as many green photosites as red or blue, and why green is the channel image formats spend the most data on. Green is a good field for spotting fine dust as well, for the same reason: the contrast between a dark speck and a bright green background is the most visible combination there is. Wipe the screen before deciding anything is a pixel fault, and view fullscreen at native resolution.
How to use the Green Screen
- The test starts on its own — no button to press and nothing to install.
- Follow the prompt in the test panel and watch the readings update live.
- Press Reset to start over with a clean slate.
About the Green Screen
The Green Screen fills your entire screen with solid green. Checking green sub-pixels — the channel the eye is most sensitive to, so faults show up here first. It runs as plain JavaScript inside the page, which means there is no upload step, no queue and no size limit imposed by a server — the only limit is your own device.
What people use it for
- Checking green sub-pixels — the channel the eye is most sensitive to, so faults show up here first.
- Checking a monitor or phone screen before a return window closes.
- Using as a plain backdrop for photography or for cleaning the screen.
Press Fullscreen above before judging anything. A colour patch surrounded by page furniture tells you very little — the panel needs to be filling the whole screen, ideally in a dark room, with any night-light or blue-light filter switched off.
Frequently asked questions
What is the difference between a dead and a stuck pixel?
A dead pixel receives no power and stays black on every colour. A stuck pixel is latched on and shows the same bright red, green or blue dot against every background. Stuck pixels sometimes recover; dead ones never do.
How do I tell a dead pixel from dust?
Dust sits on the outside of the glass and moves or disappears when you wipe the screen with a microfibre cloth. A dead pixel does not move and stays in exactly the same position on every colour.
How many dead pixels before I can return a monitor?
That depends on the manufacturer's policy, which is usually written against the ISO 9241-307 pixel fault classes. Most consumer panels are sold to a standard that tolerates several sub-pixel faults, so check the specific warranty terms — and photograph what you find while the panel is still within the return window.
Are there any usage caps on the Green Screen?
No charge and no sign-up. There is no free tier to run out of because there is no paid tier — inputtesthub.com is funded by advertising rather than by metering the tool.
Is the Green Screen safe to use with private information?
No. The Green Screen runs entirely in your browser using JavaScript. Because the work happens locally, the tool also keeps working if your connection drops, and closing the tab is all it takes to discard everything.
Who is the Green Screen for?
In practice it gets used for three things: checking green sub-pixels — the channel the eye is most sensitive to, so faults show up here first. Checking a monitor or phone screen before a return window closes. Using as a plain backdrop for photography or for cleaning the screen. It is built for exactly those cases rather than being a general-purpose tool with this bolted on.
Any caveats I should know about?
Press Fullscreen above before judging anything. A colour patch surrounded by page furniture tells you very little — the panel needs to be filling the whole screen, ideally in a dark room, with any night-light or blue-light filter switched off.
Do I need to install anything to run this test?
No installation, no extension and no driver. The Green Screen uses the browser's own device APIs and begins as soon as the page loads, so there is nothing to press first. Press Reset at any point to start over with a clean slate.
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