# Viewport

The visible area of the page; vw and vh measure it.

## What is the **viewport**?

The **viewport** is the visible area of the page in the browser window or phone screen. The `vw` and `vh` units are percentages of it.

```css
.hero { height: 100vh; }   /* fills the screen */
```

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

Updated: September 27, 2026

Source: https://www.ask-codey.com/glossary/viewport