# Cross axis

The direction across the main axis; align-items works along it.

## What is the **cross axis** in Flexbox?

The **cross axis** runs across the main axis: up and down for a row. `align-items` works along it.

```css
.row { display: flex; align-items: center; }   /* centered top to bottom */
```

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/cross-axis