<Image> (Legacy)
Examples
Starting with Next.js 13, the next/image
component was rewritten to improve both the performance and developer experience. In order to provide a backwards compatible upgrade solution, the old next/image
was renamed to next/legacy/image
.
View the new next/image
API Reference
Comparison
Compared to next/legacy/image
, the new next/image
component has the following changes:
- Removes
<span>
wrapper around<img>
in favor of native computed aspect ratio - Adds support for canonical
style
prop- Removes
layout
prop in favor ofstyle
orclassName
- Removes
objectFit
prop in favor ofstyle
orclassName
- Removes
objectPosition
prop in favor ofstyle
orclassName
- Removes
- Removes
IntersectionObserver
implementation in favor of native lazy loading- Removes
lazyBoundary
prop since there is no native equivalent - Removes
lazyRoot
prop since there is no native equivalent
- Removes
- Removes
loader
config in favor ofloader
prop - Changed
alt
prop from optional to required - Changed
onLoadingComplete
callback to receive reference to<img>
element
Required Props
The <Image />
component requires the following properties.
src
Must be one of the following:
- A statically imported image file
- A path string. This can be either an absolute external URL, or an internal path depending on the loader prop or loader configuration.
When using an external URL, you must add it to remotePatterns in next.config.js
.
width
The width
property can represent either the rendered width or original width in pixels, depending on the layout
and sizes
properties.
When using layout="intrinsic"
or layout="fixed"
the width
property represents the rendered width in pixels, so it will affect how large the image appears.
When using layout="responsive"
, layout="fill"
, the width
property represents the original width in pixels, so it will only affect the aspect ratio.
The width
property is required, except for statically imported images, or those with layout="fill"
.
height
The height
property can represent either the rendered height or original height in pixels, depending on the layout
and sizes
properties.
When using layout="intrinsic"
or layout="fixed"
the height
property represents the rendered height in pixels, so it will affect how large the image appears.
When using layout="responsive"
, layout="fill"
, the height
property represents the original height in pixels, so it will only affect the aspect ratio.
The height
property is required, except for statically imported images, or those with layout="fill"
.
Optional Props
The <Image />
component accepts a number of additional properties beyond those which are required. This section describes the most commonly-used properties of the Image component. Find details about more rarely-used properties in the Advanced Props section.
layout
The layout behavior of the image as the viewport changes size.
layout | Behavior | srcSet | sizes | Has wrapper and sizer |
---|---|---|---|---|
intrinsic (default) | Scale down to fit width of container, up to image size | 1x , 2x (based on imageSizes) | N/A | yes |
fixed | Sized to width and height exactly | 1x , 2x (based on imageSizes) | N/A | yes |
responsive | Scale to fit width of container | 640w , 750w , ... 2048w , 3840w (based on imageSizes and deviceSizes) | 100vw | yes |
fill | Grow in both X and Y axes to fill container | 640w , 750w , ... 2048w , 3840w (based on imageSizes and deviceSizes) | 100vw | yes |
- Demo the
intrinsic
layout (default)- When
intrinsic
, the image will scale the dimensions down for smaller viewports, but maintain the original dimensions for larger viewports.
- When
- Demo the
fixed
layout- When
fixed
, the image dimensions will not change as the viewport changes (no responsiveness) similar to the nativeimg
element.
- When
- Demo the
responsive
layout- When
responsive
, the image will scale the dimensions down for smaller viewports and scale up for larger viewports. - Ensure the parent element uses
display: block
in their stylesheet.
- When
- Demo the
fill
layout- When
fill
, the image will stretch both width and height to the dimensions of the parent element, provided the parent element is relative. - This is usually paired with the
objectFit
property. - Ensure the parent element has
position: relative
in their stylesheet.
- When
- Demo background image
loader
A custom function used to resolve URLs. Setting the loader as a prop on the Image component overrides the default loader defined in the images
section of next.config.js
.
A loader
is a function returning a URL string for the image, given the following parameters:
Here is an example of using a custom loader:
import Image from 'next/legacy/image'
const myLoader = ({ src, width, quality }) => {
return `https://example.com/${src}?w=${width}&q=${quality || 75}`
}
const MyImage = (props) => {
return (
<Image
loader={myLoader}
src="me.png"
alt="Picture of the author"
width={500}
height={500}
/>
)
}
sizes
A string that provides information about how wide the image will be at different breakpoints. The value of sizes
will greatly affect performance for images using layout="responsive"
or layout="fill"
. It will be ignored for images using layout="intrinsic"
or layout="fixed"
.
The sizes
property serves two important purposes related to image performance:
First, the value of sizes
is used by the browser to determine which size of the image to download, from next/legacy/image
's automatically-generated source set. When the browser chooses, it does not yet know the size of the image on the page, so it selects an image that is the same size or larger than the viewport. The sizes
property allows you to tell the browser that the image will actually be smaller than full screen. If you don't specify a sizes
value, a default value of 100vw
(full screen width) is used.
Second, the sizes
value is parsed and used to trim the values in the automatically-created source set. If the sizes
property includes sizes such as 50vw
, which represent a percentage of the viewport width, then the source set is trimmed to not include any values which are too small to ever be necessary.
For example, if you know your styling will cause an image to be full-width on mobile devices, in a 2-column layout on tablets, and a 3-column layout on desktop displays, you should include a sizes property such as the following:
import Image from 'next/legacy/image'
const Example = () => (
<div className="grid-element">
<Image
src="/example.png"
layout="fill"
sizes="(max-width: 768px) 100vw,
(max-width: 1200px) 50vw,
33vw"
/>
</div>
)
This example sizes
could have a dramatic effect on performance metrics. Without the 33vw
sizes, the image selected from the server would be 3 times as wide as it needs to be. Because file size is proportional to the square of the width, without sizes
the user would download an image that's 9 times larger than necessary.
Learn more about srcset
and sizes
:
quality
The quality of the optimized image, an integer between 1
and 100
where 100
is the best quality. Defaults to 75
.
priority
When true, the image will be considered high priority and
preload. Lazy loading is automatically disabled for images using priority
.
You should use the priority
property on any image detected as the Largest Contentful Paint (LCP) element. It may be appropriate to have multiple priority images, as different images may be the LCP element for different viewport sizes.
Should only be used when the image is visible above the fold. Defaults to false
.
placeholder
A placeholder to use while the image is loading. Possible values are blur
or empty
. Defaults to empty
.
When blur
, the blurDataURL
property will be used as the placeholder. If src
is an object from a static import and the imported image is .jpg
, .png
, .webp
, or .avif
, then blurDataURL
will be automatically populated.
For dynamic images, you must provide the blurDataURL
property. Solutions such as Plaiceholder can help with base64
generation.
When empty
, there will be no placeholder while the image is loading, only empty space.
Try it out:
- Demo the
blur
placeholder - Demo the shimmer effect with
blurDataURL
prop - Demo the color effect with
blurDataURL
prop
Advanced Props
In some cases, you may need more advanced usage. The <Image />
component optionally accepts the following advanced properties.
style
Allows passing CSS styles to the underlying image element.
Note that all layout
modes apply their own styles to the image element, and these automatic styles take precedence over the style
prop.
Also keep in mind that the required width
and height
props can interact with your styling. If you use styling to modify an image's width
, you must set the height="auto"
style as well, or your image will be distorted.
objectFit
Defines how the image will fit into its parent container when using layout="fill"
.
This value is passed to the object-fit CSS property for the src
image.
objectPosition
Defines how the image is positioned within its parent element when using layout="fill"
.
This value is passed to the object-position CSS property applied to the image.
onLoadingComplete
A callback function that is invoked once the image is completely loaded and the placeholder has been removed.
The onLoadingComplete
function accepts one parameter, an object with the following properties:
loading
Attention: This property is only meant for advanced usage. Switching an image to load with
eager
will normally hurt performance.We recommend using the
priority
property instead, which properly loads the image eagerly for nearly all use cases.
The loading behavior of the image. Defaults to lazy
.
When lazy
, defer loading the image until it reaches a calculated distance from
the viewport.
When eager
, load the image immediately.
blurDataURL
A Data URL to
be used as a placeholder image before the src
image successfully loads. Only takes effect when combined
with placeholder="blur"
.
Must be a base64-encoded image. It will be enlarged and blurred, so a very small image (10px or less) is recommended. Including larger images as placeholders may harm your application performance.
Try it out:
- Demo the default
blurDataURL
prop - Demo the shimmer effect with
blurDataURL
prop - Demo the color effect with
blurDataURL
prop
You can also generate a solid color Data URL to match the image.
lazyBoundary
A string (with similar syntax to the margin property) that acts as the bounding box used to detect the intersection of the viewport with the image and trigger lazy loading. Defaults to "200px"
.
If the image is nested in a scrollable parent element other than the root document, you will also need to assign the lazyRoot prop.
lazyRoot
A React Ref pointing to the scrollable parent element. Defaults to null
(the document viewport).
The Ref must point to a DOM element or a React component that forwards the Ref to the underlying DOM element.
Example pointing to a DOM element
import Image from 'next/legacy/image'
import React from 'react'
const Example = () => {
const lazyRoot = React.useRef(null)
return (
<div ref={lazyRoot} style={{ overflowX: 'scroll', width: '500px' }}>
<Image lazyRoot={lazyRoot} src="/one.jpg" width="500" height="500" />
<Image lazyRoot={lazyRoot} src="/two.jpg" width="500" height="500" />
</div>
)
}
Example pointing to a React component
import Image from 'next/legacy/image'
import React from 'react'
const Container = React.forwardRef((props, ref) => {
return (
<div ref={ref} style={{ overflowX: 'scroll', width: '500px' }}>
{props.children}
</div>
)
})
const Example = () => {
const lazyRoot = React.useRef(null)
return (
<Container ref={lazyRoot}>
<Image lazyRoot={lazyRoot} src="/one.jpg" width="500" height="500" />
<Image lazyRoot={lazyRoot} src="/two.jpg" width="500" height="500" />
</Container>
)
}
unoptimized
When true, the source image will be served as-is instead of changing quality,
size, or format. Defaults to false
.
import Image from 'next/image'
const UnoptimizedImage = (props) => {
return <Image {...props} unoptimized />
}
Since Next.js 12.3.0, this prop can be assigned to all images by updating next.config.js
with the following configuration:
module.exports = {
images: {
unoptimized: true,
},
}
Other Props
Other properties on the <Image />
component will be passed to the underlying
img
element with the exception of the following:
srcSet
. Use Device Sizes instead.ref
. UseonLoadingComplete
instead.decoding
. It is always"async"
.
Configuration Options
Remote Patterns
To protect your application from malicious users, configuration is required in order to use external images. This ensures that only external images from your account can be served from the Next.js Image Optimization API. These external images can be configured with the remotePatterns
property in your next.config.js
file, as shown below:
module.exports = {
images: {
remotePatterns: [
{
protocol: 'https',
hostname: 'example.com',
port: '',
pathname: '/account123/**',
search: '',
},
],
},
}
Good to know: The example above will ensure the
src
property ofnext/legacy/image
must start withhttps://example.com/account123/
and must not have a query string. Any other protocol, hostname, port, or unmatched path will respond with 400 Bad Request.
Below is an example of the remotePatterns
property in the next.config.js
file using a wildcard pattern in the hostname
:
module.exports = {
images: {
remotePatterns: [
{
protocol: 'https',
hostname: '**.example.com',
port: '',
search: '',
},
],
},
}
Good to know: The example above will ensure the
src
property ofnext/legacy/image
must start withhttps://img1.example.com
orhttps://me.avatar.example.com
or any number of subdomains. It cannot have a port or query string. Any other protocol or unmatched hostname will respond with 400 Bad Request.
Wildcard patterns can be used for both pathname
and hostname
and have the following syntax:
*
match a single path segment or subdomain**
match any number of path segments at the end or subdomains at the beginning
The **
syntax does not work in the middle of the pattern.
Good to know: When omitting
protocol
,port
,pathname
, orsearch
then the wildcard**
is implied. This is not recommended because it may allow malicious actors to optimize urls you did not intend.
Below is an example of the remotePatterns
property in the next.config.js
file using search
:
module.exports = {
images: {
remotePatterns: [
{
protocol: 'https',
hostname: 'assets.example.com',
search: '?v=1727111025337',
},
],
},
}
Good to know: The example above will ensure the
src
property ofnext/legacy/image
must start withhttps://assets.example.com
and must have the exact query string?v=1727111025337
. Any other protocol or query string will respond with 400 Bad Request.
Domains
Warning: Deprecated since Next.js 14 in favor of strict
remotePatterns
in order to protect your application from malicious users. Only usedomains
if you own all the content served from the domain.
Similar to remotePatterns
, the domains
configuration can be used to provide a list of allowed hostnames for external images.
However, the domains
configuration does not support wildcard pattern matching and it cannot restrict protocol, port, or pathname.
Below is an example of the domains
property in the next.config.js
file:
module.exports = {
images: {
domains: ['assets.acme.com'],
},
}
Loader Configuration
If you want to use a cloud provider to optimize images instead of using the Next.js built-in Image Optimization API, you can configure the loader
and path
prefix in your next.config.js
file. This allows you to use relative URLs for the Image src
and automatically generate the correct absolute URL for your provider.
module.exports = {
images: {
loader: 'imgix',
path: 'https://example.com/myaccount/',
},
}
Built-in Loaders
The following Image Optimization cloud providers are included:
- Default: Works automatically with
next dev
,next start
, or a custom server - Vercel: Works automatically when you deploy on Vercel, no configuration necessary. Learn more
- Imgix:
loader: 'imgix'
- Cloudinary:
loader: 'cloudinary'
- Akamai:
loader: 'akamai'
- Custom:
loader: 'custom'
use a custom cloud provider by implementing theloader
prop on thenext/legacy/image
component
If you need a different provider, you can use the loader
prop with next/legacy/image
.
Images can not be optimized at build time using
output: 'export'
, only on-demand. To usenext/legacy/image
withoutput: 'export'
, you will need to use a different loader than the default. Read more in the discussion.
The
next/legacy/image
component's default loader usessquoosh
because it is quick to install and suitable for a development environment. When usingnext start
in your production environment, it is strongly recommended that you installsharp
by runningnpm i sharp
in your project directory. This is not necessary for Vercel deployments, assharp
is installed automatically.
Advanced
The following configuration is for advanced use cases and is usually not necessary. If you choose to configure the properties below, you will override any changes to the Next.js defaults in future updates.
Device Sizes
If you know the expected device widths of your users, you can specify a list of device width breakpoints using the deviceSizes
property in next.config.js
. These widths are used when the next/legacy/image
component uses layout="responsive"
or layout="fill"
to ensure the correct image is served for user's device.
If no configuration is provided, the default below is used.
module.exports = {
images: {
deviceSizes: [640, 750, 828, 1080, 1200, 1920, 2048, 3840],
},
}
Image Sizes
You can specify a list of image widths using the images.imageSizes
property in your next.config.js
file. These widths are concatenated with the array of device sizes to form the full array of sizes used to generate image srcsets.
The reason there are two separate lists is that imageSizes is only used for images which provide a sizes
prop, which indicates that the image is less than the full width of the screen. Therefore, the sizes in imageSizes should all be smaller than the smallest size in deviceSizes.
If no configuration is provided, the default below is used.
module.exports = {
images: {
imageSizes: [16, 32, 48, 64, 96, 128, 256, 384],
},
}
Acceptable Formats
The default Image Optimization API will automatically detect the browser's supported image formats via the request's Accept
header.
If the Accept
head matches more than one of the configured formats, the first match in the array is used. Therefore, the array order matters. If there is no match (or the source image is animated), the Image Optimization API will fallback to the original image's format.
If no configuration is provided, the default below is used.
module.exports = {
images: {
formats: ['image/webp'],
},
}
You can enable AVIF support with the following configuration.
module.exports = {
images: {
formats: ['image/avif', 'image/webp'],
},
}
Good to know: AVIF generally takes 20% longer to encode but it compresses 20% smaller compared to WebP. This means that the first time an image is requested, it will typically be slower and then subsequent requests that are cached will be faster.
Caching Behavior
The following describes the caching algorithm for the default loader. For all other loaders, please refer to your cloud provider's documentation.
Images are optimized dynamically upon request and stored in the <distDir>/cache/images
directory. The optimized image file will be served for subsequent requests until the expiration is reached. When a request is made that matches a cached but expired file, the expired image is served stale immediately. Then the image is optimized again in the background (also called revalidation) and saved to the cache with the new expiration date.
The cache status of an image can be determined by reading the value of the x-nextjs-cache
(x-vercel-cache
when deployed on Vercel) response header. The possible values are the following:
MISS
- the path is not in the cache (occurs at most once, on the first visit)STALE
- the path is in the cache but exceeded the revalidate time so it will be updated in the backgroundHIT
- the path is in the cache and has not exceeded the revalidate time
The expiration (or rather Max Age) is defined by either the minimumCacheTTL
configuration or the upstream image Cache-Control
header, whichever is larger. Specifically, the max-age
value of the Cache-Control
header is used. If both s-maxage
and max-age
are found, then s-maxage
is preferred. The max-age
is also passed-through to any downstream clients including CDNs and browsers.
- You can configure
minimumCacheTTL
to increase the cache duration when the upstream image does not includeCache-Control
header or the value is very low. - You can configure
deviceSizes
andimageSizes
to reduce the total number of possible generated images. - You can configure formats to disable multiple formats in favor of a single image format.
Minimum Cache TTL
You can configure the Time to Live (TTL) in seconds for cached optimized images. In many cases, it's better to use a Static Image Import which will automatically hash the file contents and cache the image forever with a Cache-Control
header of immutable
.
module.exports = {
images: {
minimumCacheTTL: 60,
},
}
The expiration (or rather Max Age) of the optimized image is defined by either the minimumCacheTTL
or the upstream image Cache-Control
header, whichever is larger.
If you need to change the caching behavior per image, you can configure headers
to set the Cache-Control
header on the upstream image (e.g. /some-asset.jpg
, not /_next/image
itself).
There is no mechanism to invalidate the cache at this time, so its best to keep minimumCacheTTL
low. Otherwise you may need to manually change the src
prop or delete <distDir>/cache/images
.
Disable Static Imports
The default behavior allows you to import static files such as import icon from './icon.png'
and then pass that to the src
property.
In some cases, you may wish to disable this feature if it conflicts with other plugins that expect the import to behave differently.
You can disable static image imports inside your next.config.js
:
module.exports = {
images: {
disableStaticImages: true,
},
}
Dangerously Allow SVG
The default loader does not optimize SVG images for a few reasons. First, SVG is a vector format meaning it can be resized losslessly. Second, SVG has many of the same features as HTML/CSS, which can lead to vulnerabilities without proper Content Security Policy (CSP) headers.
Therefore, we recommended using the unoptimized
prop when the src
prop is known to be SVG. This happens automatically when src
ends with ".svg"
.
However, if you need to serve SVG images with the default Image Optimization API, you can set dangerouslyAllowSVG
inside your next.config.js
:
module.exports = {
images: {
dangerouslyAllowSVG: true,
contentDispositionType: 'attachment',
contentSecurityPolicy: "default-src 'self'; script-src 'none'; sandbox;",
},
}
In addition, it is strongly recommended to also set contentDispositionType
to force the browser to download the image, as well as contentSecurityPolicy
to prevent scripts embedded in the image from executing.
Animated Images
The default loader will automatically bypass Image Optimization for animated images and serve the image as-is.
Auto-detection for animated files is best-effort and supports GIF, APNG, and WebP. If you want to explicitly bypass Image Optimization for a given animated image, use the unoptimized prop.
Version History
Version | Changes |
---|---|
v13.0.0 | next/image renamed to next/legacy/image |
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