# lazysizes noscript/progressive enhancement extension
The noscript extension is the true ultimate progressive enhancement extension for lazySizes. It allows you to transform any HTML inside a ``noscript`` element as soon as it becomes visible.
## Markup
The ``lazyload`` class has to be added to the parent element of the ``noscript`` element and this element has to also have a ``data-noscript`` attribute. As soon as it is near the viewport the content of the ``noscript`` element will replace the content of the ``.lazyload` element.
```html
```
**Important note**: While you also can transform responsive images with this plugin, neither the ``data-sizes`` nor the ``customMedia`` features do work with the ``noscript`` extension. Also note: Android 2.x is not supported with this plugin.
## Troubleshooting: Escaped HTML entities
Normally the content of a ``noscript`` must be retrieved as text. But in some cases for example, if the ``noscript`` element was created in a XML documented/context, it must be retrieved as HTML. This can't be automatically detected.
In case this happens, you can fix this either by making sure that ``noscript`` elements are always created in a *text/html* context or by overriding the ``getNoscriptContent`` option callback:
```js
window.lazySizesConfig = window.lazySizesConfig || {};
window.lazySizesConfig.getNoscriptContent = function(noScript){
return (noScript.isXML) ? noScript.innerHTML : (noScript.textContent || noScript.innerText);
};
```
## Add IE8- support with conditional comments
The noscript extension can also be used in conjunction with conditional comments to add progressive enhancement support for IE8-:
```html
