react-imgix
provides custom components for integrating imgix into React sites and generating images server-side.
- Overview / Resources
- Installation
- Usage
- Upgrade Guides
- Browser Support
- Contributors
- Meta
Before you get started with react-imgix, it's highly recommended that you read Eric Portis' seminal article on srcset
and sizes
. This article explains the history of responsive images in responsive design, why they're necessary, and how all these technologies work together to save bandwidth and provide a better experience for users. The primary goal of react-imgix is to make these tools easier for developers to implement, so having an understanding of how they work will significantly improve your react-imgix experience.
Below are some other articles that help explain responsive imagery, and how it can work alongside imgix:
-
Using imgix with
<picture>
. Discusses the differences between art direction and resolution switching, and provides examples of how to accomplish art direction with imgix. -
Responsive Images with
srcset
and imgix. A look into how imgix can work withsrcset
andsizes
to serve the right image.
-
NPM:
npm install react-imgix
-
Yarn:
yarn add react-imgix
This module exports two transpiled versions. If a ES6-module-aware bundler is being used to consume this module, it will pick up an ES6 module version and can perform tree-shaking. If you are not using ES6 modules, you don't have to do anything
import Imgix from "react-imgix";
// in react component
<Imgix src={string} />;
For simply using as you would use an <img>
, react-imgix can be used as follows:
import Imgix from "react-imgix";
<Imgix src="https://assets.imgix.net/examples/pione.jpg" sizes="100vw" />;
Please note: 100vw
is an appropriate sizes
value for a full-bleed image. If your image is not full-bleed, you should use a different value for sizes
. Eric Portis' "Srcset and sizes" article goes into depth on how to use the sizes
attribute.
This will generate HTML similar to the following:
<img
src="https://assets.imgix.net/examples/pione.jpg?auto=format&crop=faces&ixlib=react-7.2.0"
sizes="100vw"
srcset="
https://assets.imgix.net/examples/pione.jpg?auto=format&crop=faces&ixlib=react-7.2.0&w=100 100w,
https://assets.imgix.net/examples/pione.jpg?auto=format&crop=faces&ixlib=react-7.2.0&w=200 200w,
...
"
/>
Since imgix can generate as many derivative resolutions as needed, react-imgix calculates them programmatically, using the dimensions you specify. All of this information has been placed into the srcset and sizes attributes.
Width and height known and fixed: If the width and height are known beforehand, and a fixed-size image is wanted, it is recommended that they are set explicitly:
import Imgix from "react-imgix";
<Imgix
src="https://assets.imgix.net/examples/pione.jpg"
width={100} // This sets what resolution the component should load from the CDN and the size of the resulting image
height={200}
/>;
When width and height are specified, <Imgix>
will give the image a srcset with resolution descriptors.
Width and height known but fluid: If the image's intrinsic width and height are known but a fluid size image is wanted, width and height should still be set to avoid layout shift, but they must be set via htmlAttributes
so as not to hint to <Imgix>
to produce resolution descriptors in the srcset.
import Imgix from "react-imgix";
<Imgix
src="https://assets.imgix.net/examples/pione.jpg"
sizes="(min-width: 1024px) 40vw, 90vw"
htmlAttributes={{ // These are ignored by Imgix but passed through to the <img> element
width: 200,
height: 100,
}}
/>;
In this example, <Imgix>
will produce a srcset with width descriptors.
Note This library does not run in Server Components but instead adds the "use client" directive to components. This means they are able to be used alongside Server Components (for example, as children), but they still require client-side JavaScript. Client Components are still SSRed.
React-imgix also works well on the server. Since react-imgix uses srcset
and sizes
, it allows the browser to render the correctly sized image immediately after the page has loaded.
If they are known, pass width and height attributes via htmlAttributes
to help combat layout shift.
import Imgix from "react-imgix";
<Imgix
src="https://assets.imgix.net/examples/pione.jpg"
sizes="100vw"
htmlAttributes={{
width: 400,
height: 250,
}}
/>;
If the width and height are known beforehand, and a fixed-size image is wanted, set width and height and do not set sizes
:
import Imgix from "react-imgix";
<Imgix
src="https://assets.imgix.net/examples/pione.jpg"
width={100} // This sets what resolution the component should load from the CDN and the size of the resulting image
height={200}
/>;
This component acts dynamically by default. The component will leverage srcset
and sizes
to render the right size image for its container. This is an example of this responsive behaviour.
sizes
should be set properly for this to work well, and some styling should be used to set the size of the component rendered. Without sizes
and correct styling the image might render at full-size.
./styles.css
.App {
display: flex;
}
.App > img {
margin: 10px auto;
width: 10vw;
height: 200px;
}
./app.js
import "./styles.css";
<div className="App">
<Imgix
src="https://assets.imgix.net/examples/pione.jpg"
sizes="calc(10% - 10px)"
/>
</div>;
Aspect Ratio: A developer can pass a desired aspect ratio, which will be used when
generating srcsets to resize and crop your image as specified. For the ar
parameter to take effect, ensure that the fit
parameter is set to crop
.
<div className="App">
<Imgix
src="https://assets.imgix.net/examples/pione.jpg"
sizes="calc(10% - 10px)"
imgixParams={{ ar: "16:9" }}
/>
</div>
The aspect ratio is specified in the format width:height
. Either dimension can be an integer or a float. All of the following are valid: 16:9, 5:1, 1.92:1, 1:1.67.
If the fluid, dynamic nature explained above is not desired, the width and height can be set explicitly.
import Imgix from "react-imgix";
<Imgix
src="https://assets.imgix.net/examples/pione.jpg"
width={100} // This sets what resolution the component should load from the CDN and the size of the resulting image
height={200}
/>;
Fixed image rendering will automatically append a variable q
parameter mapped to each dpr
parameter when generating a srcset. This technique is commonly used to compensate for the increased filesize of high-DPR images. Since high-DPR images are displayed at a higher pixel density on devices, image quality can be lowered to reduce overall filesize without sacrificing perceived visual quality. For more information and examples of this technique in action, see this blog post.
This behavior will respect any overriding q
value passed in via imgixParams
and can be disabled altogether with the boolean property disableQualityByDPR
.
<Imgix
src="https://domain.imgix.net/image.jpg"
width={100}
disableQualityByDPR
/>
will generate the following srcset:
https://domain.imgix.net/image.jpg?q=75&w=100&dpr=1 1x,
https://domain.imgix.net/image.jpg?q=50&w=100&dpr=2 2x,
https://domain.imgix.net/image.jpg?q=35&w=100&dpr=3 3x,
https://domain.imgix.net/image.jpg?q=23&w=100&dpr=4 4x,
https://domain.imgix.net/image.jpg?q=20&w=100&dpr=5 5x
Images can be rendered as a background behind children by using <Background />
. The component will measure the natural size of the container as determined by the CSS on the page, and will render an optimal image for those dimensions.
Example:
// In CSS
.blog-title {
width: 100vw;
height: calc(100vw - 100px);
}
// In Component (React)
import { Background } from 'react-imgix'
<Background src="https://.../image.png" className="blog-title">
<h2>Blog Title</h2>
</Background>
This component shares a lot of props that are used in the main component, such as imgixParams
, and htmlAttributes
.
As the component has to measure the element in the DOM, it will mount it first and then re-render with an image as the background image. Thus, this technique doesn't work very well with server rendering. If you'd like for this to work well with server rendering, you'll have to set a width and height manually.
Set width and height:
Setting the width and/or height explicitly is recommended if you already know these beforehand. This will save the component from having to do two render passes, and it will render a background image immediately.
This is accomplished by passing w
and h
as props to imgixParams.
<Background
src="https://.../image.png"
imgixParams={{ w: 1920, h: 500 }}
className="blog-title"
>
<h2>Blog Title</h2>
</Background>
Using the picture element you can create responsive images:
import Imgix, { Picture, Source } from "react-imgix";
<Picture>
<Source
src={src}
width={400}
htmlAttributes={{ media: "(min-width: 768px)" }}
/>
<Source
src={src}
width={200}
htmlAttributes={{ media: "(min-width: 320px)" }}
/>
<Imgix src={src} imgixParams={{ w: 100 }} />
</Picture>
In order to reduce the duplication in props, JSX supports object spread for props:
import Imgix, { Picture, Source } from "react-imgix";
const commonProps = {
src: "https://...",
imgixParams: {
fit: "crop",
crop: "faces",
},
};
<Picture>
<Source
{...commonProps}
width={400}
htmlAttributes={{ media: "(min-width: 768px)" }}
/>
<Source
{...commonProps}
width={200}
htmlAttributes={{ media: "(min-width: 320px)" }}
/>
<Imgix src={src} width={100} />
</Picture>
A warning is displayed when no fallback image is passed. This warning can be disabled in special circumstances. To disable this warning, look in the warnings section.
The <ImgixProvider>
Higher Order Component (HOC), makes its props available to any nested <Imgix>
component in your React application.
For example, by rendering <ImgixProvider>
at the top level of your application with imgixParams
defined, all your <Imgix>
components will have access to the same imgixParams
.
import React from "react";
import Imgix, { ImgixProvider } from "react-imgix";
import HomePage from "./components/HomePage";
function App() {
return (
<div className="App">
<header className="App-header">
<ImgixProvider imgixParams={{ ar: "16:9", fit: "crop" }}>
<div className="intro-blurb">{/* ... */}</div>
<div className="gallery">
<Imgix src="https://assets.imgix.net/examples/pione.jpg" />
<Imgix src="https://sdk-test.imgix.net/ساندویچ.jpg" />
</div>
</ImgixProvider>
</header>
</div>
);
}
export default App;
So that the generated HTML looks something like
<div class="gallery">
<img
src="https://assets.imgix.net/examples/pione.jpg?auto=format&ar=16%3A9&fit=crop"
...
/>
<img
src="https://sdk-test.imgix.net/%D8%B3%D8%A7%D9%86%D8%AF%D9%88%DB%8C%DA%86.jpg?auto=format&ar=16%3A9&fit=crop"
...
/>
</div>
You can take advantage of this behavior to use partial URLs with the <Imgix>
component. By defining the domain
prop on the Provider, it can be made accessible to all nested <Imgix>
components.
// inside App.jsx
{
/*... */
}
<ImgixProvider domain="assets.imgix.net">
<div className="intro-blurb">{/* ... */}s</div>
<div className="gallery">
<Imgix src="/examples/pione.jpg" />
<Imgix src="Office Background 1.png" />
</div>
</ImgixProvider>;
{
/*... */
}
Both the <Imgix>
components above will access to the domain
prop from the provider and have their relative src
paths resolve to the same domain. So that the generated HTML looks something like:
<div class="gallery">
<img src="https://assets.imgix.net/examples/pione.jpg" ... />
<img
src="https://assets.imgix.net/Office%20Background%201.png?auto=format"
...
/>
</div>
The props that <ImgixProvider>
makes accessible can also be overridden by <Imgix>
components. Any prop defined on the <Imgix>
component will override the value set by the Provider.
// inside App.jsx
{
/*... */
}
<ImgixProvider imgixParams={{ ar: "16:9", fit: "crop" }}>
<div className="intro-blurb">{/* ... */}s</div>
<div className="gallery">
<Imgix
imgixParams={{ ar: "4:2" }}
src="https://assets.imgix.net/examples/pione.jpg"
/>
<Imgix src="https://sdk-test.imgix.net/ساندویچ.jpg" />
</div>
</ImgixProvider>;
{
/*... */
}
So that the generated HTML looks something like this
<div class="gallery">
<img
src="https://assets.imgix.net/examples/pione.jpg?auto=format&ar=4%3A2&fit=crop"
...
/>
<img
src="https://sdk-test.imgix.net/%D8%B3%D8%A7%D9%86%D8%AF%D9%88%DB%8C%DA%86.jpg?ar=16%3A9&fit=crop"
...
/>
</div>
To remove a shared prop from an <Imgix>
component, the same prop can be set to undefined
on the component itself.
// inside App.jsx
{
/*... */
}
<ImgixProvider height={500}>
<div className="intro-blurb">{/* ... */}s</div>
<div className="gallery">
<Imgix src="https://assets.imgix.net/examples/pione.jpg" />
<Imgix height={undefined} src="https://sdk-test.imgix.net/ساندویچ.jpg" />
</div>
</ImgixProvider>;
{
/*... */
}
So that the generated HTML looks something like this:
<div class="gallery">
<img src="https://assets.imgix.net/examples/pione.jpg?h=500" ... />
<img
src="https://sdk-test.imgix.net/%D8%B3%D8%A7%D9%86%D8%AF%D9%88%DB%8C%DA%86.jpg"
...
/>
</div>
You can nest ImgixProvider
components to ensure that different consumers have different props.
For example to give Imgix
components different props from Picture
components, you can nest an ImgixProvider
inside of another one.
The nested Provider will change the Context for the Picture
component, essentially removing their access to the shared props provided by the root ImgixProvider
.
import React from 'react'
import Imgix, { ImgixProvider, Picture, Source } from "react-imgix";
export default function simpleImage() {
return (
<div className="imgix-simple-api-example">
{/* there props will be accessible to all the imgix components */}
<ImgixProvider
domain="assets.imgix.net"
src="/examples/pione.jpg"
imgixParams={{ fit: "crop" }}
>
<Imgix width={200} height={500} src="/examples/pione.jpg" />
<Imgix domain="sdk-test.imgix.net" src="/ساندویچ.jpg" />
<ImgixProvider
{/* since we define a new provider here, the context is redefined for any child components */}
>
<Picture>
{/* imgixParams prop is no longer defined here */}
<Source
width={100}
htmlAttributes={{ media: "(min-width: 768px)" }}
/>
<Source
width={200}
htmlAttributes={{ media: "(min-width: 800px)" }}
/>
<Imgix src="/examples/pione.jpg" />
</Picture>
</ImgixProvider>
</ImgixProvider>
</div>
)
}
Although imgix is open to feature suggestions, we might not accept the feature if it is a very specific use case. The features below are examples of what we consider general advanced use cases. Our target here is to support 95% of all the usages of normal img
, picture
, and source
elements.
If your desired feature falls outside this percentage, do not worry! You will probably still be able to achieve your feature with react-imgix's more powerful API: buildURL
.
This library exposes a pure function, buildURL
, for generating full imgix URLs given a base URL and some parameters.
import { buildURL } from "react-imgix";
buildURL("http://yourdomain.imgix.net/image.png", { w: 450, h: 100 }); // => http://yourdomain.imgix.net/image.png?auto=format&w=450&h=100&ixlib=react-x.x.x
The base URL may also contain query parameters. These will be overridden by any parameters passed in with the second parameter.
This feature can be used to create your own custom img
elements, or for use with other image components, such as React-bootstrap's Image component.
The ixlib
parameter may be disabled by: buildURL(<url>, <params>, { disableLibraryParam: true })
This library allows the developer to pass any attribute they like to the underlying DOM element with htmlAttributes
.
For example, if the the developer would like to attach a custom onLoad
callback to an img
component:
<Imgix
src="..."
sizes="..."
htmlAttributes={{
onLoad: () => handleImgOnLoad,
}}
/>
If you'd like to lazy load images, we recommend using browser-level lazy loading, with the loading
property, passed in htmlAttributes
:
<Imgix
src="..."
sizes="..."
htmlAttributes={{
loading: "lazy"
}}
/>
This property has strong browser support, and functions without additional JavaScript. Additionally, using browser-level lazy loading enables optimization of the sizes attribute with sizes="auto"
, which allows the browser to automatically calculate the optimal size for the image based on its layout.
If you need granular control over lazy-loading behavior such as loading distance, you can use the Intersection Observer API.
If you are using a library like lazysizes, you can tell the Imgix component to generate compatible attributes instead of the standard src
, srcset
, and sizes
by changing some configuration settings:
<Imgix
className="lazyload"
src="..."
sizes="..."
attributeConfig={{
src: "data-src",
srcSet: "data-srcset",
sizes: "data-sizes",
}}
/>
The same configuration is available for <Source />
components
NB: It is recommended to use the attribute change plugin in order to capture changes in the data-* attributes. Without this, changing the props to this library will have no effect on the rendered image.
If you'd like to use LQIP images, like before, we recommend using lazysizes. In order to use react-imgix with lazysizes, you can simply tell it to generate lazysizes-compatible attributes instead of the standard src
, srcset
, and sizes
by changing some configuration settings, and placing the fallback image src in the htmlAttributes:
<Imgix
className="lazyload"
src="..."
sizes="..."
attributeConfig={{
src: "data-src",
srcSet: "data-srcset",
sizes: "data-sizes",
}}
htmlAttributes={{
src: "...", // low quality image here
}}
/>
NB: If the props of the image are changed after the first load, the low quality image will replace the high quality image. In this case, the src
attribute may have to be set by modifying the DOM directly, or the lazysizes API may have to be called manually after the props are changed. In any case, this behaviour is not supported by the library maintainers, so use at your own risk.
A ref
passed to react-imgix using <Imgix ref={handleRef}>
will attach the ref to the <Imgix>
instance, rather than the DOM element. It is possible to attach a ref to the DOM element that is rendered using htmlAttributes
:
<Imgix htmlAttributes={{ ref: handleRef }}>
This works for Source and Picture elements as well.
These props are shared among Imgix and Source Components
Usually in the form: https://[your_domain].imgix.net/[image]
. Don't include any parameters.
Required only when using partial paths as src
prop for a component. IE, if src
is "/images/myImage.jpg"
, then the domain
prop needs to be defined.
For example:
<Imgix domain="assets.imgix.net" src="/examples/pione.jpg">
imgix params to add to the image src
.
For example:
<Imgix imgixParams={{ mask: "ellipse" }} />
Specified the developer's expected size of the image element when rendered on the page. Similar to width. E.g. 100vw
, calc(50vw - 50px)
, 500px
. Highly recommended when not passing width
or height
. Eric Portis' "Srcset and sizes" article goes into depth on how to use the sizes
attribute.
className
applied to top level component. To set className
on the image itself see htmlAttributes
.
Force images to be a certain height.
Force images to be a certain width.
Disable generation of variable width src sets to enable responsiveness.
By default this component adds a parameter to the generated url to help imgix with analytics and support for this library. This can be disabled by setting this prop to true
.
By default this component encodes the url path in the src and srcSet. This can be disabled by setting this prop to true
. For more information about how imgix path encoding works, please refer to the imgix/js-core docs.
Any other attributes to add to the html node (example: alt
, data-*
, className
).
Called on componentDidMount
with the mounted DOM node as an argument.
Allows the src, srcset, and sizes attributes to be remapped to different HTML attributes. For example:
attributeConfig={{
src: 'data-src',
srcSet: 'data-srcset',
sizes: 'data-sizes'
}}
This re-maps src to data-src
, srcSet to data-srcset
, etc.
Disable generation of variable q
parameters when rendering a fixed-size image.
Allows customizing the behavior of the srcset generation. Valid options are widths
, widthTolerance
, minWidth
, maxWidth
, and devicePixelRatios
. See @imgix/js-core for documentation of these options.
className
applied to top level component. To set className
on the image itself see htmlAttributes
.
Called on componentDidMount
with the mounted DOM node as an argument.
Any other attributes to add to the html node (example: alt
, data-*
, className
).
Usually in the form: https://[your_domain].imgix.net/[image]
. Don't include any parameters.
imgix params to add to the image src
. This is also how width and height can be explicitly set. For more information about this, see the "Background" section above.
For example:
<Background imgixParams={{ mask: "ellipse" }} />
className
applied to top level component. To set className
on the image itself see htmlAttributes
.
By default this component adds a parameter to the generated url to help imgix with analytics and support for this library. This can be disabled by setting this prop to true
.
Any other attributes to add to the html node (example: alt
, data-*
, className
).
This library triggers some warnings under certain situations to try aid developers in upgrading or to fail-fast. These can sometimes be incorrect due to the difficulty in detecting error situations. This is annoying, and so there is a way to turn them off. This is not recommended for beginners, but if you are using custom components or other advanced features, it is likely you will have to turn them off.
Warnings can be turned off with the public config API, PublicConfigAPI
, which is exported at the top-level.
// in init script/application startup
import { PublicConfigAPI } from "react-imgix";
PublicConfigAPI.disableWarning('<warningName>');
//... rest of app startup
React.render(...);
Warnings can also be enabled with PublicConfigAPI.enableWarning('<warningName>')
The warnings available are:
warningName |
Description |
---|---|
fallbackImage | Triggered when there is no <img> or <Imgix> at the end of the children when using <Picture> . A fallback image is crucial to ensure the image renders correctly when the browser cannot match against the sources provided |
sizesAttribute | This library requires a sizes prop to be passed so that the images can render responsively. This should only turned off in very special circumstances. |
invalidARFormat | Warnings thrown when the ar imgix parameter is not passed in the correct format (w:h ) |
This release brings the react-imgix API more in-line with that of imgix's rendering service.
The largest change users will notice is that this project's component will no longer generate a default fit=crop
parameter. The original intention behind this was that generated images would maintain aspect ratio when at least one of the dimensions were specified. However, the default imgix API behavior sets fit=clip
, which is now reflected in this project.
Although this may not cause breaking changes for all users, it can result in unusual rendered image behavior in some cases. As such, we would rather err on the side of caution and provide users the ability to opt in to these changes via a major release.
If you are currently relying on the default generation of fit=crop
when rendering images, you will now have to manually specify it when invoking the component:
<Imgix
src="https://assets.imgix.net/examples/pione.jpg"
sizes="100vw"
imgixParams={{ fit: "crop" }}
/>
The other major change relates to how the component determines an image's aspect ratio. Instead of appending a calculated height h=
value based on specified dimensions, the URL string will now be built using the imgix aspect ratio parameter ar=
. Luckily, the interface for specifying an aspect ratio is no different from before. However, users will have to pass in the fit=crop
parameter in order for it to take effect:
<Imgix
src="http://assets.imgix.net/examples/pione.jpg"
width={400}
imgixParams={{ ar: "2:1", fit: "crop" }}
/>
This is a very large update to this library with a lot of breaking changes. We apologise for any issues this may cause, and we have tried to reduce the number of breaking changes. We have also worked to batch up all these changes into one release to reduce its impacts. We do not plan on making breaking changes for a while after this, and will be focussed on adding features.
The largest change in this major version bump is the move to width-based srcSet
and sizes
for responsiveness. This has a host of benefits, including better server rendering, better responsiveness, less potential for bugs, and performance improvements. This does mean that the old fitting-to-container-size behaviour has been removed. If this is necessary, an example of how this can be achieved can be found here
To upgrade to version 8, the following changes should be made.
-
A
sizes
prop should be added to all usages of<Imgix>
. Ifsizes
is new to you (or even if it's not), Eric's seminal article onsrcset
andsizes
is highly recommended. -
Change all usages of
type='picture'
to<Picture>
andtype='source'
to<Source>
// this... <Imgix type='picture'> <Imgix type='source' src={src}> <Imgix type='source' src={src}> </Imgix> // becomes... <Picture> <Source src={src}> <Source src={src}> </Picture>
See Picture support for more information.
-
Remove all usage of
type='bg'
as it is no longer supported. It was decided that it was too hard to implement this feature consistently. If you would still like to use this feature, please give this issue a thumbs up: https://github.com/imgix/react-imgix/issues/160 If we get enough requests for this, we will re-implement it. -
Remove props
aggressiveLoad
,component
,fluid
,precision
as they are no longer used. -
Change all usages of
defaultHeight
anddefaultWidth
towidth
andheight
props. -
Rename
generateSrcSet
todisableSrcSet
and invert the value passed down as the prop's value. i.e.generateSrcSet={false}
becomesdisableSrcSet={true}
or simplydisableSrcSet
-
If support is needed for a browser which does not support the new usage of srcSet (such as IE 11), we recommended adding a polyfill, such as the great Picturefill.
- By default, browsers that don't support
srcset
,sizes
, orpicture
will gracefully fall back to the defaultimg
src
when appropriate. If you want to provide a fully-responsive experience for these browsers, react-imgix works great alongside Picturefill! - We support the latest version of Google Chrome (which automatically updates whenever it detects that a new version of the browser is available). We also support the current and previous major releases of desktop Firefox, Internet Explorer, and Safari on a rolling basis. Mobile support is tested on the most recent minor version of the current and previous major release for the default browser on iOS and Android (e.g., iOS 9.2 and 8.4). Each time a new version is released, we begin supporting that version and stop supporting the third most recent version.
This browser support is made possible by the great support from BrowserStack.
Thanks goes to these wonderful people (emoji key):
This project follows the all-contributors specification. Contributions of any kind welcome, but please review the contribution guidelines before getting started!
React-imgix was originally created by Frederick Fogerty. It's licensed under the ISC license (see the license file for more info).