Keyboard typing repeated letters

Key repeats are one of the most common keyboard problems. Sometimes it is just the expected operating-system behaviour, but in other cases it points to a hardware or driver fault. This guide shows how to tell the two apart and what to do in each scenario.

When it's normal behaviour

Modern operating systems repeat a key automatically when it is held down for more than half a second. This behaviour is controlled by the system, not by the keyboard itself. It's useful for list navigation and text editing.

When it's a fault

If the key repeats even with short, individual taps, it's usually a fault. Typical symptoms include:

• Letters duplicated or tripled in quick succession.
• Repeats even with light, short taps.
• Only one specific key shows the issue.
• The problem appears in every program, browser or app.

How to confirm using the keyboard test

Open the online keyboard test, hover the cursor over the virtual keyboard and press the suspect key once, quickly. If the history shows two or three consecutive down events for the same code just milliseconds apart, the repeat is real and comes from the hardware.

Possible fixes

1. Clean it: remove the keycap and use compressed air. Dust is the most common cause.
2. Replace the switch: on hot-swap mechanical keyboards, swap the faulty switch.
3. Reinstall the driver: remove it and install the latest version.
4. Test on another system: confirm it isn't software.
5. Replace the keyboard: when repair isn't worth it.

Relation to other symptoms

Repeating keys often show up alongsidethe keyboard typing by itself and dead keys. Investigating one symptom usually clarifies the others.