Keyboard test: check every key in your browser
This free online keyboard tester lets you check that every key on your keyboard works, right in the browser. Nothing to install and nothing to sign up for. Press keys and each one lights up on the on-screen layout the instant it registers, so you can sweep the whole board and immediately see any key that fails to respond. It works for mechanical keyboards, laptop keyboards and external USB or Bluetooth keyboards alike, because the test reads the physical key position rather than the character it types.
How to test your keyboard
Press every key one at a time and watch the matching key highlight. A key that lights up is working; a key that never lights up is the one to investigate. Keys you have already pressed stay marked so you can tell at a glance which ones are left. The counter shows how many of the keys on the selected layout you have covered. Use the reset button to start a fresh sweep, for example when testing a second keyboard.
Windows, Mac, Linux and Android keyboards
The same physical key has a different name on every system, which is why a keyboard tester that only knows one layout is confusing. The key beside the space bar is the Windows key on a PC, Command (⌘) on a Mac, Super on Linux and Search on an Android keyboard; browsers call all four "Meta". Apple keyboards also say option instead of Alt, return instead of Enter and delete instead of Backspace, have no Menu or Insert key, and put clear and = on the numeric keypad where a PC has Num Lock.
This tester detects your operating system and draws the matching keyboard, so the legends on screen are the ones printed on the keys in front of you. The layout buttons above the board let you switch between the Windows, macOS, Linux and Android boards at any time - useful for a PC keyboard plugged into a Mac, a Bluetooth keyboard paired to a tablet, or simply checking a keyboard that is not the one you are sitting at. If we cannot tell which system you are on, the standard 104-key Windows board is shown. Your choice is remembered for your next visit, and switching never loses the keys you have already tested.
ANSI vs ISO: US and European keyboards
The other thing that changes from country to country is the shape of the keyboard itself. The US standard, ANSI, has 104 keys on a full-size board: a wide flat Enter with the backslash key directly above it, and a long left Shift. It is what ships in the United States, Canada, Australia and most of Asia. The European standard, ISO, has 105: the Enter key is tall and L-shaped, spanning two rows and overhanging the key to its left; backslash moves down to the home row beside the apostrophe; a whole extra key appears between the left Shift and Z, which is why the left Shift is short; and the right Alt becomes Alt Gr. ISO is used across Europe and Latin America.
Pick the one that matches the keyboard in front of you and the counter changes to 104 or 105 keys accordingly, so a complete sweep really does mean every key. The extra ISO key is reported by browsers as IntlBackslash, and it is worth testing precisely because software often forgets it exists. The two positions that ISO adds or moves are the only ones whose printed symbol varies by country - shown here as # and <, the most common European symbols, where a UK board prints # and \, a German one # and <, and a French one * and <. The physical positions, which is what the test actually measures, are identical everywhere.
Key rollover and N-key rollover (NKRO)
Rollover is how many keys your keyboard can register at the same time. Hold several keys down together and the tester reports the maximum it saw pressed simultaneously. Cheaper membrane keyboards often stop at 2 - 3 keys, which is fine for typing but can drop inputs in games; gaming keyboards advertise 6-key rollover or full N-key rollover (NKRO), where every key is read independently. This is the fastest way to check whether your keyboard will keep up with fast key combinations.
Testing for ghosting
Ghosting is when pressing a specific combination of keys causes a key you did not press to register, or blocks one you did. It comes from how the keyboard matrix is wired. To check for it, hold three or four keys in the same area of the keyboard at once and watch whether the highlighted keys match exactly what you are pressing. If an extra key lights up, or one of yours refuses to, that combination ghosts.
Finding stuck, dead or chattering keys
A dead key never registers no matter how hard you press. It will not light up here. A stuck key registers on its own or stays down; you will see it highlighted as active when you are not touching it. Chatter is a key that fires twice from one press, which shows up as repeated entries in the key-history log. Spotting which specific key is faulty is the first step before cleaning it, remapping it, or claiming a warranty.
Everything stays on your device
The test runs entirely in your browser using the standard keyboard events the page receives. Nothing you press is recorded, stored or sent anywhere, so it is safe to type normally while testing. Some keys (such as a laptop Fn key, or dedicated media and brightness keys) are handled by the hardware or operating system before the browser sees them, so they may not appear here even though they work.
