> For the complete documentation index, see [llms.txt](https://sygnal.gitbook.io/sygnal-webflow-components/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://sygnal.gitbook.io/sygnal-webflow-components/designer-gaps/boolean-attributes.md).

# Boolean Attributes

{% hint style="success" %}
Webflow's Custom Element appears to automatically recognize and handle boolean attributes.  These can be bound to a data source. Any non-NULL value will render the value-less attribute, and NULL values will suppress it.
{% endhint %}

ere’s a comprehensive list of **all standard boolean attributes** in HTML. These attributes are **true when present**, regardless of value, and **false when absent**.

#### Notes:

* Boolean attributes **do not require a value**.
* Setting them to `"false"` does **not** turn them off — omit the attribute instead.

{% hint style="warning" %}
This determination does not appear to be smart about the tag used, e.g. `disabled` will be recognized and handled as a boolean attribute even on HTML tags that do not support `disabled` as a boolean attribute. 
{% endhint %}

## Full List of Boolean Attributes in HTML 

Haven't tested any except `required` and `checked`. 

But here is a cGPT list; 

| Attribute         | Applies To                          | Effect When Present                                    |
| ----------------- | ----------------------------------- | ------------------------------------------------------ |
| `allowfullscreen` | `<iframe>`                          | Allows fullscreen rendering                            |
| `async`           | `<script>`                          | Executes script asynchronously                         |
| `autofocus`       | `<input>`, `<textarea>`, `<select>` | Sets focus on page load                                |
| `autoplay`        | `<audio>`, `<video>`                | Starts playback automatically                          |
| `checked`         | \`\<input type="checkbox            | radio">\`                                              |
| `controls`        | `<audio>`, `<video>`                | Displays playback controls                             |
| `default`         | `<track>`, `<optgroup>`, `<option>` | Marks as default selection                             |
| `defer`           | `<script>`                          | Defers execution until HTML parsing completes          |
| `disabled`        | Form elements                       | Disables input or control                              |
| `formnovalidate`  | `<button>`, `<input type="submit">` | Prevents form validation on submit                     |
| `hidden`          | All elements                        | Hides the element from view/rendering                  |
| `inert`           | All elements (experimental)         | Makes the element and its children non-interactive     |
| `ismap`           | `<img>`                             | Makes image a server-side image map                    |
| `itemscope`       | Any element                         | Declares microdata item                                |
| `loop`            | `<audio>`, `<video>`                | Repeats playback automatically                         |
| `multiple`        | `<select>`, `<input type="file">`   | Allows multiple selections                             |
| `muted`           | `<audio>`, `<video>`                | Mutes media                                            |
| `nomodule`        | `<script>`                          | Prevents execution in module-supporting browsers       |
| `novalidate`      | `<form>`                            | Disables form validation                               |
| `open`            | `<details>`                         | Expands the disclosure widget                          |
| `playsinline`     | `<video>`                           | Plays video inline instead of fullscreen               |
| `readonly`        | `<input>`, `<textarea>`             | Prevents user editing, but allows focus                |
| `required`        | `<input>`, `<select>`, `<textarea>` | Makes field required for form submission               |
| `reversed`        | `<ol>`                              | Reverses the list order                                |
| `selected`        | `<option>`                          | Pre-selects the option                                 |
| `tristate`        | Custom use, not standard            | Sometimes used in ARIA contexts (not native)           |
| `translate`       | All elements                        | Indicates if content should be translated (`yes`/`no`) |
| `typemustmatch`   | `<object>`                          | Requires correct MIME type                             |

***

#### ⚠️ Notes:

* Boolean attributes **do not require a value**.
* Setting them to `"false"` does **not** turn them off — omit the attribute instead.