# Reflow

The browser redoing layout after a size or position change.

## What is a **reflow**?

A **reflow** is the browser redoing layout after something changes size or position. Doing it too often makes a page feel slow.

```javascript
// slow: reads and writes in a loop cause a reflow each time
items.forEach(el => { el.style.width = el.offsetWidth + 10 + "px"; });
```

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

Updated: September 27, 2026

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