useHead()
The useHead()
composable is for managing the document head. It provides a type-safe, reactive API to define, update, and remove head elements like title, meta tags, scripts, and more. It's the core composable used across all frameworks in the Unhead ecosystem.
import { useHead } from '@unhead/react'
const entry = useHead({
title: 'My Page',
})
// update
entry.patch({ title: 'new Title' })
// remove
entry.dispose()
How It Works
The composable works by queuing your input to be resolved when the head is rendered:
- It registers your head configuration in a queue
- When the document head is being rendered (client-side or during SSR), all queued entries are:
- Resolved (including any functions, promises or reactive values)
- Deduplicated (removing redundant tags) - see Handling Duplicates
- Sorted (based on tag priority) - see Tag Positions
- Merged when appropriate
- The resolved tags are then rendered to the document head
This queue-based approach enables powerful features like deduplication, async resolution, and priority-based rendering while maintaining optimal performance.
Reactivity Model
useHead()
provides reactivity through two main mechanisms:
- Framework Integration: When used with frameworks it automatically integrates with the framework's reactivity system
- Manual API: The returned
ActiveHeadEntry
object withpatch()
anddispose()
methods lets you manually update or remove head entries
API Reference
function useHead(input: UseHeadInput, options?: HeadEntryOptions): ActiveHeadEntry
Parameters
Parameter | Type | Required | Description |
---|---|---|---|
input | Head | Yes | The head configuration object |
options | HeadEntryOptions | No | Configuration options for the head entry |
Returns
interface ActiveHeadEntry {
/**
* Update the head entry with new values
*/
patch: (input: Partial<UseHeadInput>) => void
/**
* Remove the head entry
*/
dispose: () => void
}
Input Schema
The input object accepts the following properties:
interface Head<E extends MergeHead = SchemaAugmentations> {
// Document title
title?: string | Promise<string>
// Title template (function or string with %s placeholder)
titleTemplate?: string | null | ((title?: string) => string | null)
// Template parameters for dynamic replacements
templateParams?: { separator?: string } & Record<string, string | Record<string, string>>
// HTML tag collections
base?: Base<E['base']>
link?: Link<E['link']>[]
meta?: Meta<E['meta']>[]
style?: (Style<E['style']> | string)[]
script?: (Script<E['script']> | string)[]
noscript?: (Noscript<E['noscript']> | string)[]
// Element attributes
htmlAttrs?: HtmlAttributes<E['htmlAttrs']>
bodyAttrs?: BodyAttributes<E['bodyAttrs']>
}
The input is deeply resolved allowing you to provide any value as a function. This can be useful for lazily resolving values when the head tags are being rendered.
import { useHead } from '@unhead/react'
const title = useMyTitle()
useHead({
// just works
title: () => 'Dynamic Title',
meta: [
() => ({
name: 'description',
content: () => `Description for ${title.value}`
}),
]
})
Options
The options
parameter allows you to configure the behavior of the head entry:
export interface HeadEntryOptions {
// Whether to process template parameters in the input
// - Requires the TemplateParams plugin
processTemplateParams?: boolean
// Priority of tags for determining render order
tagPriority?: number | 'critical' | 'high' | 'low' | `before:${string}` | `after:${string}`
// Where to position tags in the document
tagPosition?: 'head' | 'bodyClose' | 'bodyOpen'
// Custom head instance
head?: Unhead
}
Setting any of these will apply that rule to all tags within the entry. For example if we want to push several meta tags with low priority, we can do:
import { useHead } from '@unhead/react'
useHead({
meta: [
{ name: 'description', content: 'fallback description' },
{ name: 'author', content: 'fallback author' }
]
}, {
tagPriority: 'low'
})
tagPriority
option is particularly useful for controlling render order when you have multiple head entries that might contain similar tags.Reactivity
Manual Control
For more granular control, you can use the returned API:
import { useHead } from '@unhead/react'
// Create the head entry
const headControl = useHead({
title: 'Initial Title'
})
// Later update specific fields
headControl.patch({
title: 'Updated Title',
meta: [
{ name: 'description', content: 'New description' }
]
})
// Remove the entry entirely when needed
headControl.dispose()
Use cases for manual control:
- Updating head after asynchronous data loading
- Conditional changes based on user interactions
- Managing head from global state
- Creating temporary modifications
For framework-specific reactivity details, see the guides for each specific framework.
Security Considerations
useHead()
function applies minimal sanitization to improve developer experience.Do not use this function with untrusted or third-party input. It cannot guarantee safety when handling unknown content.For XSS protection, either:
- Sanitize your input before passing it to
useHead()
- Use the safer alternatives:
- useSeoMeta() for SEO metadata
- useHeadSafe() for general head management
Advanced Examples
Title Template
import { useHead } from '@unhead/react'
useHead({
titleTemplate: title => `${title} - My Site`,
title: 'Home Page'
})
// Results in: "Home Page - My Site"
For more details on title templates, see the Titles guide.
Combining Multiple Head Entries
import { useHead } from '@unhead/react'
// Global site defaults
useHead({
titleTemplate: '%s | My Website',
meta: [
{ name: 'og:site_name', content: 'My Website' }
]
})
// Page-specific entries (will be merged with globals)
useHead({
title: 'Product Page',
meta: [
{ name: 'description', content: 'This product is amazing' }
]
})
Async Data Loading
import { useHead } from '@unhead/react'
import { computed, ref } from 'vue'
// Initial setup
const data = ref(null)
const loading = ref(true)
const error = ref(null)
const headControl = useHead({
title: computed(() => data.value
? `${data.value.name} - Product`
: loading.value
? 'Loading...'
: 'Product Not Found')
})
// Fetch data and update head
async function fetchProduct(id) {
try {
loading.value = true
data.value = await api.getProduct(id)
}
catch (err) {
error.value = err
}
finally {
loading.value = false
}
}
Priority-Based Tag Ordering
import { useHead } from '@unhead/react'
// Critical meta tags (early in <head>)
useHead({
meta: [
{ charset: 'utf-8' },
{ name: 'viewport', content: 'width=device-width, initial-scale=1' }
]
}, { tagPriority: 'critical' })
// Default priority tags (middle of <head>)
useHead({
meta: [
{ name: 'description', content: 'My website description' }
]
})
// Low priority tags (end of <head>)
useHead({
meta: [
{ name: 'author', content: 'Jane Doe' }
]
}, { tagPriority: 'low' })
Common Use Cases
Here are some common use cases for useHead()
:
- Setting page-specific metadata for SEO (consider using useSeoMeta() for a more convenient API)
- Managing document title and favicon (see Titles guide)
- Adding external scripts and stylesheets (consider using useScript() for scripts)
- Setting Open Graph and Twitter card tags
For ready-to-use implementations of common patterns, see our Starter Recipes.