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Gatsby Head API

Examples

  • Using Gatsby Head

Support for the Gatsby Head API was added in gatsby@4.19.0.

Gatsby includes a built-in Head export that allows you to add elements to the document head of your pages.

Compared to react-helmet or other similar solutions, Gatsby Head is easier to use, more performant, has a smaller bundle size, and supports the latest React features.

Using Gatsby Head in your page

By exporting a named function called Head you can set the metadata for a page:

The arrow function syntax is also valid:

When defining multiple metatags use React Fragments:

You can also re-export a Head function in your page from another file:

Deduplication

To avoid duplicate tags in your <head> you can use the id property on your tags to make sure that only one is rendered. Given the following example:

In this case only the second <link id="icon" rel="icon" href="icon-specific-for-this-page" /> is rendered. In a list of items with the same id, the last item wins and is used in the HTML.

Usage notes

You’ll need to be aware of these things when using Gatsby Head:

  • You can only define the Head export inside a page, not in a component.
  • The contents of Gatsby Head get cleared upon unmounting the page, so make sure that each page defines what it needs in its <head>.
  • The Head function needs to return valid JSX.
  • Valid tags inside the Head function are: link, meta, style, title, base, script, and noscript.
  • Data block <script> tags such as <script type="application/ld+json"> can go in the Head function, but dynamic scripts are better loaded with the Gatsby Script Component in your pages or components.
  • As of now, Head can’t access React Context that you defined in the wrapRootElement API.

Properties

The Head function receives these properties:

  • location.pathname: Returns the Location object’s URL’s path
  • params: The URL parameters when the page has a matchPath (when using client-only routes)
  • data: Data passed into the page via an exported GraphQL query
  • pageContext: A context object which is passed in during the creation of the page

Editing <html> and <body>

The scope of Gatsby Head is to modify the <head> portion of your pages. To edit other parts like <html> or <body>, please use the Gatsby Server Rendering APIs.

One common use case is to modify the <html> element to e.g. add a lang attribute. You can achieve this the following way:

Additional Resources

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