01
White Screen
Fills your entire screen with solid white. Cleaning the screen, spotting dust and dark…
Overscan & Screen Geometry Test
A grid with corner brackets and an edge border that reveals overscan, off-centre images and non-linear scaling.
Screen Tests
Nothing uploaded
No sign-up
Free, unlimited
The test starts automatically — follow the prompts above.
In short
Overscan is a television behaviour left over from the analogue era, when broadcast pictures had ragged edges that were deliberately hidden by displaying slightly less than the full frame. Digital sets inherited it, and the result is that a computer connected to a TV often has its edges cut off — the taskbar half off-screen, the corners of windows missing. If the corner brackets in this test are clipped, that is what is happening. The fix is on the display rather than the computer, and it has a different name on every brand: look for Just Scan, 1:1 Pixel, Screen Fit, Full Pixel, Native or PC mode. Setting the input label to "PC" often switches it off automatically along with several other processing features. On a real monitor this rarely applies — if a monitor is clipping edges, the cause is usually a scaling or underscan setting in the graphics driver instead, which both Nvidia and AMD expose in their control panels.
How to use the Overscan & Screen Geometry Test
- 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 Overscan & Screen Geometry Test
The Overscan & Screen Geometry Test a grid with corner brackets and an edge border that reveals overscan, off-centre images and non-linear scaling. 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
- Setting up a television used as a computer monitor.
- Checking that nothing is being cut off at the edges.
- Verifying image centring after changing a cable.
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
My corners are cut off. What do I change?
Look for a picture-size setting on the display itself, named Just Scan, 1:1 Pixel, Screen Fit, Full Pixel or PC mode depending on the brand. Televisions overscan by default for historical broadcast reasons and it is almost always switchable.
Why does this matter on a monitor?
It usually does not — overscan is a television behaviour. If a proper monitor clips the edges, the graphics driver has a scaling or underscan setting applied.
Are there any usage caps on the Overscan & Screen Geometry Test?
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 utility.
Is the Overscan & Screen Geometry Test safe to use with private information?
No. The Overscan & Screen Geometry Test runs entirely in your browser using JavaScript. Because the work happens locally, the utility also keeps working if your connection drops, and closing the tab is all it takes to discard everything.
What problem does the Overscan & Screen Geometry Test solve?
In practice it gets used for three things: setting up a television used as a computer monitor. Checking that nothing is being cut off at the edges. Verifying image centring after changing a cable. It is built for exactly those cases rather than being a general-purpose tool with this bolted on.
Is there anything to watch out for?
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 Overscan & Screen Geometry Test 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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