# Boolean attribute

An attribute whose presence means true and whose absence means false.

## What is **Boolean attribute**?

**Boolean attribute** — An attribute whose presence means true and whose absence means false.

```html
<button disabled>Sold out</button>
```

Level: Novice · [More HTML terms at this level](https://www.ask-codey.com/glossary/subjects/html/novice)

Updated: September 27, 2026

Source: https://www.ask-codey.com/glossary/boolean-attribute