--- title: "Assets (CSS, JavaScript, media)" manual: "TYPO3 Explained" version: "main" permalink: "https://docs.typo3.org/permalink/t3coreapi:assets@main" source: "ApiOverview/Assets/Index.rst" rendered: "2026-09-22T15:26:06+00:00" --- # Assets (CSS, JavaScript, media) {#assets} ****Table of Contents**** - [Asset collector](https://docs.typo3.org/permalink/t3coreapi:asset-collector-1@main) - [Using the page renderer to add assets](https://docs.typo3.org/permalink/t3coreapi:using-the-page-renderer-to-add-assets@main) The TYPO3 component responsible for rendering the HTML and adding assets to a TYPO3 frontend or backend page is called `\TYPO3\CMS\Core\Page\PageRenderer`. The `PageRenderer` collects all assets to be rendered and finally generates the necessary tags. TYPO3 no longer supports frontend asset concatenation or pre-compression in the Core. The PageRenderer therefore does not concatenate or pre-compress CSS and JavaScript files in TYPO3 v14. There are multiple ways to add assets to the `PageRenderer` in TYPO3. For configuration options via TypoScript (usually used for the main theme files), see the [TypoScript Reference](https://docs.typo3.org/m/typo3/reference-typoscript/main/en-us/TopLevelObjects/Page/Index.html#setup-page-includecss-array). In extensions, both directly using the `PageRenderer` as well as using the more convenient `AssetCollector` is possible. ## Asset collector {#asset-collector} With the `\TYPO3\CMS\Core\Page\AssetCollector` class, CSS and JavaScript code (inline or external) can be added multiple times, but rendered only once in the output. The class may be used directly in PHP code or the assets can be added via the `` and `` ViewHelpers. The `priority` flag (default: `false`) controls where the asset is inserted: - JavaScript will be output inside `` if `$priority == true`, or at the bottom of the `` tag if `$priority == false`. - CSS will always be output inside ``, yet grouped by `$priority`. The asset collector helps to work with content elements as components, effectively reducing the CSS to be loaded. It takes advantage of HTTP/2, which removes the necessity to concatenate all files in one file. The asset collector class is implemented as a singleton (`\TYPO3\CMS\Core\SingletonInterface`). It replaces various other existing options in TypoScript and [methods in PHP](https://docs.typo3.org/permalink/t3coreapi:assets-other-methods@main) for inserting JavaScript and CSS code. The asset collector also collects information about images on a page, which can be used in cached and non-cached components. The `AssetCollector` option `external` can be used for asset files using `$assetCollector->addStyleSheet()` or `$assetCollector->addJavaScript()`. If set all processing of the asset URI (like the addition of the cache busting parameter) is skipped and the input path will be used as-is in the resulting HTML tag. ### The asset collector API {#asset-collector-api} - **class AssetCollector** - *Fully qualified name:* `\TYPO3\CMS\Core\Page\AssetCollector` The Asset Collector is responsible for keeping track of \- everything within \