---
module: [kind=event] key_up
see: keys For a lookup table of the given keys.
---

<!--
SPDX-FileCopyrightText: 2021 The CC: Tweaked Developers

SPDX-License-Identifier: MPL-2.0
-->

Fired whenever a key is released (or the terminal is closed while a key was being pressed).

This event returns a numerical "key code" (for instance, <kbd>F1</kbd> is 290). This value may vary between versions and
so it is recommended to use the constants in the [`keys`] API rather than hard coding numeric values.

## Return values
1. [`string`]: The event name.
2. [`number`]: The numerical key value of the key pressed.

## Example
Prints each key released on the keyboard whenever a [`key_up`] event is fired.

```lua
while true do
  local event, key = os.pullEvent("key_up")
  local name = keys.getName(key) or "unknown key"
  print(name .. " was released.")
end
```