Why does my keyboard type the same letter twice?

You tap a key once, but two letters appear. It might happen with just one key, or across the whole keyboard. The cause could be a key that is sticking, a setting that repeats keys too quickly, or a connection problem.

Start by checking whether the keyboard registers a quick, single tap more than once. The Keyboard Test lets you check keys in your browser and see whether the problem follows a particular key.

Check whether a key registers twice

1. Open the Keyboard Test and click the page if it asks you to focus the test.
2. Tap the problem key once, quickly, then release it. Do not hold it down, because holding a key normally makes it repeat.
3. Try the key several times, with a short pause between taps. Check whether one tap registers more than once or the key appears to stay pressed after you release it.
4. Test other keys nearby, then type in a plain text field, such as a blank document. If possible, connect another keyboard and try the same letters.

A browser test can show what the keyboard sends to the computer, but it cannot identify the exact cause on its own. Comparing a few keys and trying another keyboard helps narrow it down.

What the result means

One key registers more than once after a quick tap

If the same key repeats in the test and in other apps, the switch may be sticking or failing. Dirt, crumbs, liquid, or wear can make a key send extra signals. Try the physical checks below before deciding the keyboard needs repair.

Several keys repeat, or typing speed affects the problem

A repeat setting may be too fast, or an accessibility feature may be changing how the keyboard handles presses. If the issue happens across many keys, check these settings before blaming the hardware.

The problem happens only in one app

The keyboard may be fine. The app could be processing input incorrectly, or a text expansion, macro, or add-on could be inserting extra characters. Try another app and temporarily turn off keyboard-related extensions or utilities.

The problem stops with another keyboard

The original keyboard, its cable, or its wireless connection is the likely cause. If the same problem continues with different keyboards, focus on the computer's settings or software instead.

A held key repeats, but a quick tap does not

This is usually normal key repeat. A computer repeats a character when you hold a key down. If it starts repeating after only a brief touch, adjust the repeat delay in your system settings.

How to fix it

1. Check for a stuck or dirty key. Turn off or unplug the keyboard before cleaning it. Use a soft brush or compressed air around the problem key, and do not pour liquid onto the keyboard. If liquid was spilled, stop using it and follow the manufacturer's cleaning instructions.
2. Slow down key repeat. On Windows 11, open Control Panel and go to Hardware and Sound › Keyboard. Move Repeat delay toward Long, then test again. On macOS, open System Settings › Keyboard and increase Delay until repeat. These settings affect how quickly a held key begins repeating.
3. Check accessibility keyboard settings. On Windows 11, open Settings › Accessibility › Keyboard and check whether Filter Keys is on. On macOS, open System Settings › Accessibility › Keyboard and check Slow Keys. These features change how the system accepts key presses, so turn them off temporarily if you do not use them.
4. Reconnect a wireless keyboard. Replace or recharge its batteries, move the receiver to another USB port, and reconnect Bluetooth if needed. Keep the keyboard close to the computer while testing.
5. Restart the computer and check for updates. Restarting can clear a temporary input problem. Install system updates, and if the issue began after a keyboard driver or utility update, check the keyboard maker's support instructions.
6. Compare with another keyboard. Connect a known-working keyboard to the same computer. If it types normally, the original keyboard is the likely source. If both repeat, revisit the system settings or test in another user account.

When the keyboard itself is faulty

A hardware fault is likely when the same key sends extra presses on more than one computer, even after cleaning and checking repeat settings. A wired keyboard that changes behavior when you move its cable may have a damaged cable or connector. For a laptop keyboard, a single failing key can sometimes be repaired, but spills or problems affecting many keys often need professional service. Check the warranty before opening the device. For a separate keyboard, replacement may cost less than repair.

Why holding a key makes it repeat

Key repeat is an operating system feature, not necessarily a fault. The repeat delay sets how long you must hold a key before characters begin appearing repeatedly. The repeat rate controls how quickly they continue. Adjusting the delay can help if a light touch or a slightly slow release produces extra letters, but it will not repair a switch that sends multiple signals from one quick tap.