日本語English

Touch Screen Test

Draw touch trails and count the most fingers on the screen at once. Fill a grid to find areas that do not respond, and see pressure and contact size on devices that provide them. A mouse or pen works too.

On-device・No uploadMobile friendlyWorks offline

Your files and input are processed only inside your browser on this device and are never uploaded to our servers.

  • Touching 0
  • Max at once 0
  • Coverage 0%

Draw here with a finger, pen or mouse. Several fingers at once are drawn in different colors.

Inside the area, page scrolling, pinch zoom and the long-press menu are suppressed. The control bar at the top is not part of the test area.

This device does not report touch input. You can still try the trails and the grid with a mouse (one point at a time).
Contact record
Contacts now
0
Most contacts at once
0
Of which fingers (touch)
0
Times touched
0
Interrupted by the browser
0
Last input type
—
navigator.maxTouchPoints
0 — Reported as not touch-capable
Primary input is a finger (pointer: coarse)
No
Finding unresponsive areas

—

Switch to the “Grid” view and sweep the whole screen to fill the cells. A cell that will not fill suggests that area may not respond to touch (a screen protector, dirt or a case can also cause this).

Pressure & contact size
Pressure
Not available (no varying values received)
Contact size (CSS px)
Not available (no value reported)

Pressure and contact size come only from supporting devices, pens and browsers. Many screens report a fixed value or nothing.

Tips
  • Edges and corners are the most likely to respond poorly — sweep all four corners.
  • Wipe the screen and compare with and without the screen protector or case to narrow down the cause.
  • If the count does not rise when you add a finger, or “Interrupted by the browser” rises while you are still touching, device gesture settings or the screen itself may be involved.

Touches are only counted on this page — nothing is stored or sent.

How to use

  1. Test areaThree fingers at once

    Sweep the area with fingers

  2. TrailsOne color per finger
    Max at once3 points

    Count contacts and draw trails

  3. Grid coverageUnfilled cells: check

    Fill the grid to find dead spots

Trace touches, then fill a grid to find dead spots

  1. Drag a finger across the test area above. Trails are drawn, and each finger gets its own color and number.

  2. Add fingers one by one and check that “Max at once” goes up. The limit the device reports is shown below (navigator.maxTouchPoints).

  3. Switch to the “Grid” view and sweep the whole screen. Cells that never fill are candidates for areas that respond poorly.

  4. Press “Full screen” to test the whole display. The control bar at the top is outside the test area.

  5. Pressure and contact size appear on supporting pens and devices. Use “Reset” to clear the record and start over.

What it does

Simultaneous finger count

Counts contacts now and the maximum so far. Each finger gets its own color and number on the trail, and the type of the latest input (finger, mouse or pen) is shown.

A grid for unresponsive areas

Splits the screen into cells, fills the ones you touch and shows the coverage. A fast swipe still counts every cell along its path.

Pressure & contact size

Shows pressure and contact size delivered by Pointer Events. When values never change, it says “not available” instead of presenting a fixed value as a measurement.

No stray gestures

In the test area the page does not scroll, pinch-zoom or open the long-press menu (touch-action and context-menu handling).

Full screen & mouse

Uses the Fullscreen API where available, and a page-covering layer elsewhere. On a PC without touch you can still try trails and the grid with a mouse.

Use cases

  • A phone or tablet seems unresponsive in one spot, or feels sluggish
  • Check whether a screen protector or case makes the edges respond poorly
  • Get a rough idea of a screen that moves by itself or drops out when more fingers are added
  • See whether a touch laptop or business device recognizes several fingers at once
  • Check that a stylus or tablet pen delivers pressure and contact size to the browser

Capability matrix

FeatureSupportNotes
Counting the most simultaneous touches actually madeSupported—
Trails and filling touched grid cellsSupported—
Pressure and contact sizePartialOnly on supporting devices, pens and browsers; shown as unavailable when the values never change
The device’s maximum touch pointsPartialIt is the value in navigator.maxTouchPoints and may differ from what is really recognized
Deciding whether the touch panel is physically faultyNot supportedScreen protectors, dirt, cases and OS settings also change the response. Ask the maker or a repair service for a diagnosis
Precise finger area, tilt or hover measurementNot supportedOnly the values the browser delivers are shown
Fully disabling browser and OS gesturesPartialEdge swipes and other actions the OS handles first cannot be stopped

Limits & notes

  • The grid counts the touch position (the center of contact). A wide fingertip may touch neighboring cells, but only the center cell is filled.
  • Going full screen changes the size of the test area, so the trails and grid start over.
  • Swipes from the screen edge (back, home, notifications) are handled by the OS and may not be recorded.
  • The newest 200 trails and about 5,000 points per trail are drawn. Older trails disappear past 200, and a trail stops drawing past 5,000 points, but the grid and counts still update.

Privacy & safety

Touches are only counted on this page — nothing is stored or sent, and the record disappears when you close the page.

FAQ

How many touch points can this check?
It counts how many contacts you actually make at once. It also shows the limit the device reports (navigator.maxTouchPoints), but that reported value may not match what is really recognized.
Part of my touch screen does not respond. Is it broken?
In the “Grid” view, sweep the whole screen and note which cells stay empty. Dirt, a screen protector or a case can cause this too, so the tool alone cannot say it is broken. Wipe it, remove the protector or case, restart, and contact a repair service if it persists.
Pressure says “not available”
Most screens cannot sense pressure and browsers then report a fixed value such as 0.5. When it never varies, the tool shows it as unavailable. Pressure-sensitive pens and some tablets provide real values.
Can I use it on a PC with a mouse?
Yes. Drag with the mouse to try the trails and grid. Only one point can be touched at once, so you need a touch screen to check multi-touch.
The page scrolls or a menu opens during the test
These are suppressed inside the test area. Actions the OS handles first, such as edge swipes, cannot be stopped from the browser. If full screen does not help, check the device’s gesture settings.
Is my touch record sent anywhere?
No. Everything is counted on this page and nothing is stored or sent.

Display Test

Show your screen in full-screen solid colors to look for dead pixels and stuck-on pixels by eye. Gradient steps, fine lines, text sharpness and uniformity patterns are included, along with resolution, color gamut and an estimated refresh rate.

No upload

Mouse & Wheel Test

Test all five mouse buttons and the wheel, and automatically catch “chatter” — single clicks registering as double clicks. Double-click interval, wheel counts, polling rate (Hz) and drag breaks are measured in numbers.

No upload

Keyboard Test

Each key lights up on the on-screen keyboard as you press it, so dead keys stand out immediately. Supports US and Japanese JIS layouts with numpad, and measures maximum simultaneous keys and chatter (one press registering twice).

No upload

Webcam Test

Check your camera, its real resolution and frame rate in one click. If it doesn’t work, you’ll see the cause — permission, another app using it, not connected — and how to fix it. Nothing is recorded or uploaded.

No upload

Gamepad Test

Connect a controller and press a button to see pressed states and analog values (triggers 0–1) in real time. Stick drift is measured as the offset from centre while untouched, and rolling the rim shows how round the circle is.

No upload

Browser Inspector

A clear list of everything your browser shows to websites without asking — browser, OS, screen, language, GPU — plus support for 60+ features such as WebGPU and video codecs. Results are shown on the spot and never sent anywhere.

No upload

Last updated: