# Transition duration

Sets how long a transition takes.

## What does `transition-duration` do?

`transition-duration` sets how long a transition takes, in seconds or milliseconds.

```css
.menu { transition-duration: 250ms; }
```

Level: Journeyman · [More CSS terms at this level](https://www.ask-codey.com/glossary/subjects/css/journeyman)

Updated: September 27, 2026

Source: https://www.ask-codey.com/glossary/transition-duration