# Bad value “true” for attribute “controls” on element “audio”.

> Canonical HTML version: https://rocketvalidator.com/html-validation/bad-value-true-for-attribute-controls-on-element-audio
> Attribution: Rocket Validator (https://rocketvalidator.com)
> License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/)

The `controls` attribute on `<audio>` is a boolean attribute, so it takes no value: write `controls`, not `controls="true"`.

A boolean attribute is on when it's present and off when it's absent. The HTML specification allows three forms: the bare name (`controls`), an empty value (`controls=""`), or the attribute's own name as the value (`controls="controls"`). Any other value is invalid, `"true"` included.

Browsers still show the player for `controls="true"`, because they only check whether the attribute exists. For the same reason, `controls="false"` doesn't hide the controls. To hide the browser's controls, remove the attribute. The validator rejects `controls="false"` as a bad value too.

This markup often comes from a template or script that prints a boolean variable straight into the attribute. Output the attribute name when the value is true, and leave the attribute out when it's false.

## Invalid example

```html
<audio controls="true" src="episode.mp3">
  <a href="episode.mp3">Download the episode</a>
</audio>
```

## Valid example

```html
<audio controls src="episode.mp3">
  <a href="episode.mp3">Download the episode</a>
</audio>
```