Why is my keyboard typing double letters?

If every key doubles, it is usually a Windows setting or a driver problem. If only one or two keys double, the physical switch under those keys is worn or dirty, a fault called key chatter.

How do I stop my keyboard from typing two letters?

Turn on Filter Keys in Settings, Accessibility, Keyboard, which tells Windows to ignore unintended repeated keystrokes. Also lengthen the repeat delay and update the keyboard driver.

How do I fix keyboard chatter on a mechanical keyboard?

Power off, pop off the affected keycap, and clean the switch with compressed air or a little isopropyl alcohol. If it keeps chattering, the switch is worn and needs replacing.

Keyboard Typing Double Letters? How to Fix It

Quick answer: A keyboard typing double letters has one of two causes. If every key doubles, it is usually a Windows setting or driver — turn on Filter Keys and update the driver. If only one or two keys double, the physical switch is worn or dirty and needs cleaning.

First, find out which: open the keyboard test and press a few keys once each. Note whether every key registers twice or only certain keys do — that tells you whether this is software or hardware.

First, tell software from hardware

If every key doubles, the cause is almost always a Windows setting or driver. If only one or a few keys double while the rest are fine, those switches are worn or dirty — a hardware fault called key chatter. Match your situation to the right section below.

Fix double typing caused by settings

1. Turn on Filter Keys

This is the most reliable software fix. Go to Settings → Accessibility → Keyboard, turn on Filter keys, and enable "Ignore unintended keystrokes (bounce keys)". Windows will then drop the accidental repeats.

2. Lengthen the repeat delay

A very short repeat delay turns a normal tap into two letters. Open Control Panel → Keyboard and drag the Repeat delay slider toward Long, then apply.

3. Update or reinstall the keyboard driver

Open Device Manager, expand Keyboards, right-click your keyboard and choose Update driver. If that fails, choose Uninstall device and restart — Windows reinstalls it automatically on boot.

Fix a worn or dirty key

If only specific keys double, clean them. Power off or unplug the keyboard, then blow compressed air into the key seam. On a mechanical board you can pop off the keycap and dab a little isopropyl alcohol on the switch. For a wireless keyboard, low batteries can also cause misfires, so replace or recharge them. If a switch keeps chattering after cleaning, it is worn and needs replacing. This is the same switch-wear problem behind a mouse that double-clicks on its own .

Why did my keyboard suddenly start double typing?

A sudden onset across all keys usually points to a changed setting, a recent driver update, or a stuck modifier key — start with Filter Keys and the driver. Sudden doubling on a single key is the first sign of that switch wearing out, so clean it and watch whether it returns.

Confirm the fix

After the fix, run the keyboard test again and tap each problem key once. Every press should light up exactly one key with no repeats.