Test every key on a laptop keyboard — 13", 14", 15.6" and 17.3" boards, with or without a number pad.
Simply press any key on your keyboard to test it — if it works it will turn green
0Keys Pressed0Total Keys0%Tested
QWERTY on the US ANSI shape: a wide flat Enter and a full-length left Shift. Standard key positions, with no vendor-specific extras.
Ctrl+W, Ctrl+T, Ctrl+N, Alt+Tab and the Windows or Command key are reserved by the browser and the operating system. No web page receives them, so they cannot be tested here or anywhere else in a browser.
Keys shown greyed out with a dashed outline cannot be tested: your keyboard handles them internally and the browser never receives a key event for them. They are excluded from the totals, so 100% stays reachable.
At a glance
Key counts and layout facts
Detail
Value
Common layouts
13 and 14 inch, 15.6 inch, 17.3 inch
Testable keys (13 to 14 inch)
83 keys
Testable keys (15.6 and 17.3 inch)
100 keys
Number pad
15.6 and 17.3 inch only
Function row
Yes — usually half height
Arrow keys
Yes — integrated, often half height
Fn key
Present, never reportable
Brand differences
ThinkPads place Fn left of Ctrl
A laptop keyboard in numbers
Every figure describes the 15.6-inch board this page opens on.
100
Testable keys101 physical keys, of which Fn can never report.
1
Repair, not a replacementA dead key means opening the chassis, not buying a board.
17
Number pad keysSqueezed into a narrower column than a desktop pad.
2
Common Fn positionsBottom-left on ThinkPads, second from left elsewhere.
How to test a laptop keyboard
Test on the built-in board, not on an external one plugged into it.
1
Match the screen size first
Pick 13/14-inch for a compact board with no number pad, 15.6-inch for a compact pad, or 17.3-inch for a full-size pad. Set the brand to Lenovo if you are on a ThinkPad, which places Fn at the bottom-left corner instead of second from the left.
2
Work every row including the function row
Laptop function rows double as media and brightness controls. Press F1 to F12 directly. If your laptop is set to media-first, the F-keys need Fn held down — and then the board sends the real F-key code, which will light up here.
3
Finish with the pad and the arrows
On a 15.6-inch board the pad column is narrower than a desktop pad, so press each key at its centre. The arrow keys are usually half height and tucked under the right Shift.
What to check on a laptop keyboard
Five checks that matter more when the board is soldered into the chassis.
Neighbouring keys failing together
Liquid damage shows as a cluster or a straight line of failures, because those keys share a matrix trace. Scattered single failures point at debris instead.
Fn is drawn but untestable
Every laptop has Fn and no browser can see it. It is hatched on the board and left out of the total, so 100% stays reachable on 100 keys.
The Fn and Ctrl order
ThinkPads put Fn in the bottom-left corner with Ctrl beside it. Most other makers reverse that. Set the brand selector to match before deciding a key is in the wrong place.
Keys that need a firmer press
Scissor switches have very short travel. A key needing a deliberate press usually has debris under the scissor mechanism rather than a failed contact.
Test on a second machine only if external
A soldered laptop board cannot be moved, so isolate software faults by plugging in a USB keyboard instead and testing that.
Everything about this layout
The shape, the trade-offs and what to watch for when testing it.
01
Which laptop layout is yours?
Laptop keyboards fall into three broad shapes. Machines with a 13 or 14 inch screen almost never have room for a number pad, so they run a compact 83-key layout with the navigation keys folded into a right-hand column and the arrows tucked under a shortened right Shift.
Machines with a 15.6 inch screen usually do fit a number pad, but only by squeezing its columns narrower than the main keys — which is why the pad on a 15 inch laptop feels cramped in a way a desktop pad does not. That gives 100 testable keys.
A 17.3 inch chassis fits both a full-width pad and larger key caps, which is the real ergonomic argument for a machine that size. The key count is the same 100; the keys are simply bigger.
02
Fn on a laptop is not testable, and that is normal
Every laptop keyboard has an Fn key, usually at the bottom left, and it will never turn green on this test. The keyboard controller uses it to change what other keys report — Fn plus F2 might send a brightness command — but Fn itself never becomes a key event that reaches your browser.
It is drawn on the board here with a dashed outline and excluded from the totals, so a fully working laptop keyboard still reaches 100%.
The same applies to the special functions printed on the function row: brightness, volume, keyboard backlight, aeroplane mode and screen mirroring are all handled by firmware or a vendor driver. If your F-keys are set to send those by default, you may need to hold Fn to send a real F1 to F12 — which is exactly what this test will show.
03
Telling hardware faults from software ones
Before opening anything, plug in a USB keyboard and test the same keys on it. If the external board is fine and the built-in one is not, the fault is in the laptop keyboard, its ribbon cable, or its connector on the motherboard.
If a whole row or a contiguous block fails at once, suspect the ribbon cable rather than the keys. Ribbons work loose from vibration and from chassis flex, and on many machines reseating one is a far smaller job than replacing the keyboard.
If scattered individual keys fail with no pattern, that is usually the membrane or a worn scissor mechanism under those specific caps, which is a keyboard replacement rather than a repair.
04
Liquid, dust and the keys most likely to go
Laptop keyboards sit directly above the components you least want liquid in, and the failure pattern after a spill is distinctive: keys near the spill fail immediately, then more fail over the following days as residue dries and corrodes contacts. If you are testing after a spill, retest a week later before declaring it fixed.
Dust failures look different — usually a single key that works intermittently, feels slightly mushy, or needs a harder press than its neighbours. Compressed air across the key at a shallow angle clears most of it without dismantling anything.
The keys that fail most often are the ones used most: space, Backspace, Enter, E, A and the left Shift. If one of those is failing on a machine more than three or four years old, wear is the likeliest explanation.
Laptop boards by screen size
Chassis width decides which keys fit.
Testable key count and features by laptop size
Layout
Testable keys
Function row
Arrow keys
Number pad
13 inch / 14 inch
83
Yes
Integrated
No
15.6 inch
100
Yes
Integrated
Squeezed
17.3 inch
100
Yes
Integrated
Full width
A 17.3-inch chassis fits larger keycaps and a full-width pad column; a 15.6-inch board keeps the same key count but narrows the pad to fit.
Fixing a laptop keyboard
Four faults that behave differently on a built-in board.
1A group of neighbouring keys stopped after a spill
On the test:Several adjacent caps fail together while the rest of the board works.
Power off and disconnect immediately if the spill is recent. Do not test a wet board.
Note which keys failed. A cluster or straight line means a shared trace under the membrane.
Dry the board fully — 48 hours is a realistic minimum for anything sugary.
Expect a keyboard replacement rather than a repair. Laptop membranes are not economically repairable.
2The function keys need Fn held down
On the test:F1 to F12 only light while Fn is held.
Look for an Fn Lock key, often Esc or Fn plus Esc, which inverts the behaviour.
Change the action-key setting in your BIOS or UEFI, where most manufacturers expose it.
Note that either way the board sends real F-key codes, which is why they light here.
3A key works but needs a hard press
On the test:The cap registers only on a deliberate press.
Press the key ten times and count how many register.
Lift the keycap carefully — laptop caps clip onto a scissor mechanism and break easily.
Clear debris from under the scissor with compressed air.
Replace the individual cap and scissor, which are available for most models, before replacing the whole board.
4The whole keyboard is dead
On the test:No key lights at all.
Plug in a USB keyboard and test that here. Working means the fault is the built-in board.
Reseat the internal ribbon cable, which is a common failure after a drop.
Check Device Manager or System Information for a keyboard controller error.
Take it to a service centre if the ribbon is intact. A dead laptop board is a chassis-open repair.
Frequently asked questions
Why does my laptop Fn key not work on this test?
It cannot be tested by any website. Fn is handled inside the keyboard controller to change what other keys send, and it never becomes a browser key event. It is drawn greyed out here and excluded from the total, so a working laptop still reaches 100%.
My F1 to F12 keys change the volume instead. Is that a fault?
No. Most laptops ship with the function row set to send media and brightness commands by default, and require Fn to send a real F-key. Many machines let you invert that in the BIOS or with a vendor utility, often labelled Fn Lock or Action Keys.
How do I know if it is the keyboard or the software?
Plug in an external USB keyboard and test the same keys. If they work externally but not internally, the fault is in the laptop keyboard or its cable. If they fail on both, the cause is software — a stuck modifier, a remapping tool, or a language layout.
Can I fix a single dead laptop key myself?
Sometimes. If it is debris, compressed air or carefully lifting the keycap and cleaning underneath may solve it. If the scissor mechanism has broken, replacement caps and clips are cheap and widely available for common models. If the membrane beneath has failed, the whole keyboard needs replacing.
Does the Lenovo brand setting change the test?
Yes, on laptop layouts. ThinkPads place Fn at the bottom-left corner with Ctrl to its right, the reverse of most other manufacturers. Selecting Lenovo in the Brand dropdown swaps those two keys on the on-screen board so it matches your hardware.
Test another keyboard
Every layout below opens with its own board ready to test.
