Key Code Checker

Features

• Press any key to see key, code, keyCode, which and the ASCII value at once
• Each field is labelled with what it follows — the character, the physical position, or a legacy value
• Printable characters come with decimal and hex ASCII (`A` is 65 / 0x41)
• Named keys come with their ASCII control code (Enter is 13 / CR, Delete is 127 / DEL) — the source of the keyCode-vs-ASCII confusion
• Modifiers held down at the same time are listed (Ctrl + Shift)
• Auto-repeat events are flagged, which is what you need to detect a key being held
• IME composition is called out explicitly (during it `key` is `Process`, not a bug)
• A reference of 100+ keys, searchable by name, code, keyCode or ASCII value
• Left and right Shift / Ctrl / Alt are separate entries — only `code` can tell them apart
• The full 0–127 ASCII table, with control characters shown as abbreviations instead of 33 blank cells
• Combinations with Ctrl / Alt / Cmd are not intercepted, so your browser shortcuts keep working

How to use

1. Click the detection box at the top of the page, then press any key
2. The result list immediately shows that key’s key, code, keyCode, ASCII value and modifiers
3. Press more keys to keep going — there is no button to click
4. Search the reference below by name or value, or browse the full 0–127 ASCII table

FAQ

keyCode is deprecated, so why look it up?

Because it is the spec that was deprecated, not the fact that it appears in code. Existing projects, older libraries and a large amount of still-running sample code use `event.keyCode`, and reading them means knowing what those numbers mean. Writing new code needs the same reference in reverse — to confirm whether a given key should now be read from `key` or `code`. So it is listed alongside the other two, marked as deprecated, rather than hidden.

Why is Delete keyCode 46 but ASCII 127?

The two numbers answer different questions. `keyCode` says which key was pressed, and the Delete key carries the value 46. ASCII says which character was produced, and Delete is 127 (DEL). Enter is the same story with a twist: its `keyCode` of 13 happens to equal its ASCII control code 13 (CR), purely because that key has produced that byte since the teletype era. The tool shows the two columns separately so this stays visible instead of being conflated.

Should I use key or code in my own code?

It depends on whether you mean the character or the position. Keyboard shortcuts (Ctrl+S and friends) should use `code`, which tracks the physical key and keeps working when the user switches to a French or Russian layout. Anything about what the user actually typed should use `key`, which is what input handling, shortcut hints and games want. The historical failure mode is precisely why `keyCode` was deprecated: shortcuts written with it break on non-US keyboards.

Why does my Chinese or Japanese IME show Process?

Because at that moment the key press has not become a character yet. While the IME is composing, the browser reports `key` as `Process` and `keyCode` as 229 — and the tool additionally flags the composition. It is not a bug but a real signal: to know what the user actually entered you have to read after `compositionend`, since reading only `keydown` turns a whole sentence into a run of `Process` events.

Why does Ctrl+W not get intercepted on this page?

On purpose. The page only intercepts the default action of a few keys, and only while the detection box has focus and no modifier is held: Space and the arrow keys, so the page does not scroll away, and `/` for Firefox quick find. Anything with Ctrl, Alt or Cmd is let through, because those belong to the browser and the operating system — swallowing Ctrl+W (close tab), F5 (reload) or F12 (dev tools) would just make people think their browser is broken.