react-optimized-image

Features:

• Optimize images using WebAssembly (runs in every environment)
• React components for different use-cases (responsive images, WebP conversion, lazy loading placeholders, image manipulation, ...)
• Build cache for images for faster builds
• Convert to WebP automatically during a webpack build
• Inline small images automatically
• ...

Table of contents

• Requirements
• Installation
• Usage
  • Image components
• Global image config
• License

Requirements

This image components requires optimized-images-loader to already be installed and configured.

If you are using Next.js, you can use the next-optimized-images plugin instead for easier configuration.

Installation

npm install react-optimized-image

Add the react-optimized-image/plugin babel plugin to your .babelrc file. If you don't yet have a .babelrc file, create one with the following content:

1{
2  "plugins": ["react-optimized-image/plugin"]
3}

Usage

You can now import or require your images directly in your react components:

1import React from 'react';
2import Img from 'react-optimized-image';
3import Header from './images/header.jpg';
4
5export default () => (
6  <div>
7    {/* with import statement ..*/}
8    <Img src={Header} />
9
10    {/* ..or an inline require */}
11    <Img src={require('./images/my-small-image.png')} />
12  </div>
13);
14
15/**
16 * Results in:
17 *
18 * <div>
19 *   <img src="/_next/static/chunks/images/my-image-5216de428a8e8bd01a4aa3673d2d1391.jpg" />
20 *   <img src="data:image/png;base64,..." />
21 * </div>
22 */

Image components

For easier use and full typescript support, this plugin provides some image components.

• Img
• Svg

Img

The Img component can be used to include a normal image. Additionally, it can create a WebP fallback and provide different sizes for different viewports.

Usage

1import Img from 'react-optimized-image';
2import MyImage from './images/my-image.jpg';
3
4export default () => (
5  <>
6    <h1>Normal optimized image</h1>
7    <Img src={MyImage} />
8
9    <h1>Image will be resized to 400px width</h1>
10    <Img src={MyImage} sizes={[400]} />
11
12    <h1>A WebP image will be served in two sizes: 400px and 800px</h1>
13    <h2>As a fallback, a jpeg image will be provided (also in both sizes)</h2>
14    <Img src={MyImage} webp sizes={[400, 800]} />
15  </>
16);
17
18/**
19 * Results in:
20 *
21 * <h1>Normal optimized image</h1>
22 * <img src="/_next/static/chunks/images/my-image-5216de428a8e8bd01a4aa3673d2d1391.jpg" />
23 *
24 * <h1>Image will be resized to 400px width</h1>
25 * <img src="/_next/static/chunks/images/my-image-572812a2b04ed76f93f05bf57563c35d.jpg" />
26 *
27 * <h1>A WebP image will be served in two sizes: 400px and 800px</h1>
28 * <h2>As a fallback, a jpeg image will be provided (also in both sizes)</h2>
29 * <picture>
30 *  <source type="image/webp" srcset="/_next/static/chunks/images/image-0cc3dc9faff2e36867d4db3de15a7b32.webp" media="(max-width: 400px)">
31 *  <source type="image/webp" srcset="/_next/static/chunks/images/image-08ce4cc7914a4d75ca48e9ba0d5c65da.webp" media="(min-width: 401px)">
32 *  <source type="image/jpeg" srcset="/_next/static/chunks/images/image-132d7f8860bcb758e97e54686fa0e240.jpg" media="(max-width: 400px)">
33 *  <source type="image/jpeg" srcset="/_next/static/chunks/images/image-9df4a476716a33461114a459e64301df.jpg" media="(min-width: 401px)">
34 *  <img src="/_next/static/chunks/images/image-0f5726efb3915365a877921f93f004cd.jpg"></picture>
35 * </picture>
36 */

Properties

Prop	Required	Type	Description
src	yes	string	Source image.
webp		boolean	If true, the image will get converted to WebP. For browsers which don't support WebP, an image in the original format will be served.
sizes		number[]	Resize the image to the given width. If only one size is present, an <img> tag will get generated, otherwise a <picture> tag for multiple sizes.
densities		number[]	Default: [1] Specifies the supported pixel densities. For example, to generate images for retina displays, set this value to [1, 2].
breakpoints		number[]	Specifies the breakpoints used to decide which image size to use (when the size property is present). If no breakpoints are specified, they will automatically be set to match the image sizes which is good for full-width images but result in too big images in other cases. The breakpoints should have the same order as the image sizes. Example for this query: sizes={[400, 800, 1200]} breakpoints={[600, 1000]} For widths 0px-600px the 400px image will be used, for 601px-1000px the 800px image will be used and for everything larger than 1001px, the 1200px image will be used.
inline		boolean	If true, the image will get forced to an inline data-uri (e.g. data:image/png;base64,...).
url		boolean	If true, the image will get forced to be referenced with an url, even if it is a small image and would get inlined by default.
original		boolean	If true, the image will not get optimized (but still resized if the sizes property is present).
withDimensions		boolean	If true, width and height attributes will be added automatically to the <img> tag with values extracted from the original image. These values will always be overwritten when explicitly specified.
type		string	So you don't have to repeat yourself by setting the same sizes or other properties on many images, specify the image type which equals to one in your global image config.
anything else		ImgHTMLAttributes	All other properties will be directly passed to the <img> tag. So it would for example be possible to use native lazy-loading with loading="lazy".

Svg

The Svg includes an svg file directly into the HTML so it can be styled by CSS. If you don't want to include them directly in the HTML, you can also use svg images together with the Img component which will reference it by the URL.

Usage

1import { Svg } from 'react-optimized-image';
2import Icon from './icons/my-icon.svg';
3
4export default () => (
5  <>
6    <h1>SVG will be directly included in the HTML</h1>
7    <Svg src={Icon} className="fill-red" />
8  </>
9);
10
11/**
12 * Results in:
13 *
14 * <span><svg class="fill-red" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" width="280" height="330"><g><path>...</path></g></svg></span>
15 */

Properties

Prop	Required	Type	Description
src	yes	string	Source image.
className		string	Class to apply to the <svg> tag.

Global image config

The images.config.js file contains default image optimization options and is located in the root of your project.

Available options:

Option	Type	Description
default	ImgProps	Properties specified within the default key will get applied to all usages of the Img components. All properties of the Img component can be set. For example, to convert all your images to WebP, set { webp: true }.
types	Record<string, ImgProps>	Instead of specifying options for all images with the default key, you can create as many image types as you want. Those can also contain all properties of the Img component. The options specified in the default key will also get applied here if they are not overwritten.

Example

1// images.config.js
2
3module.exports = {
4  default: {
5    webp: true,
6  },
7  types: {
8    thumbnail: {
9      sizes: [200, 400],
10      breakpoints: [800],
11      webp: false,
12    },
13  },
14};

This will convert all images to WebP. The images with the thumbnail type will be generated in two sizes (200, 400) but not converted to WebP. If webp: false would not be present, it would get inherited from the default key.

1import React from 'react';
2import Img from 'react-optimized-image';
3import MyImage from './images/my-image.jpg';
4
5export default () => (
6  <div>
7    {/* This will get converted into a WebP image (while still providing a fallback image). */}
8    <Img src={MyImage} />
9
10    {/* This will be provided in to sizes (200, 400) but not get converted to WebP. */}
11    <Img src={MyImage} type="thumbnail" />
12  </div>
13);

License

Licensed under the MIT license.

© Copyright Cyril Wanner