About KeyboardAnalyzer

In the fall of 2025, the E key on my laptop started acting up. Sometimes one press typed two e's. Sometimes a press did nothing at all.

I did what everyone does first: I opened an online keyboard tester and pressed every key, one by one. Every key lit up. The problem didn't go away.

Then I spent a long time reading Reddit threads, and found out I wasn't alone:

• Someone's C and D keys did nothing when pressed alone, but pressed together with F they typed completely unrelated letters.
• Someone's R key stopped working whenever they held Shift+Alt. They thought the keyboard was broken, but it had simply hit its limit on how many keys it can register at once.
• Someone's mouse double-clicked now and then. They asked how to confirm it was faulty, and the answer they got was: "If you're suspicious, it probably is."

What these people were missing wasn't another page where a key lights up when you press it. They needed a tool that could answer "what exactly is going on with mine?" Is it chatter from a worn switch? A multi-key conflict (ghosting)? A driver or system setting? Should I clean it, replace the keyboard, or contact support?

So I built KeyboardAnalyzer. It tries to do three things well:

1. Explain what's actually happening: chatter, ghosting, and unresponsive keys are tested and explained separately, not just shown as a light.
2. Be honest about what a web page can't do: browsers can't see the Fn key or firmware layers, and they can't measure true hardware latency. When something can't be tested here, we say so plainly.
3. Work the moment you open it: no software to install, no sign-up, and your keystrokes are processed only in your browser, never uploaded.

My E key came back after a good cleaning. The site stayed.

If your keyboard has a strange problem that this site can't detect, write to [email protected]. Every odd case makes this tool a little better.