This special image optimize webpack loader can:
-
Help you [encode image / inline image] and [compress image / minify image] when loaded with webpack.
-
Help you tranform PNG/JPG images into WEBP when needed.
Its special encoding(inlining) ability is stronger than url-loader, especially useful for performance-optimization scenarios. And it will compress images automatically both for emited image file
or inlined images string
, without complicated configurations.
To begin, you'll need to install img-optimize-loader
:
$ npm install img-optimize-loader --save-dev
Then, all you need to do is adding the img-optimize-loader
to your webpack
config.
You don't need to specify extra loaders like
file-loader
orurl-loader
for your images.img-optimize-loader
will automaticlly handle everything.
For example:
webpack.config.js
module.exports = {
module: {
rules: [
{
test: /\.(png|jpe?g|webp|git|svg|)$/i,
use: [
{
loader: 'img-optimize-loader',
},
],
},
],
},
};
You can import your image. Compression and encoding will happen according to your configuration.
import file from 'image.png';
Encode image with
base64
,utf8
,latin1
,hex
,ascii
,binary
,ucs2
Inline image into JS / CSS files
When I use url-loader
to encode images, I can only depend on limit configuration to decide whether to enable encodeing. As we know, the image whose size was smaller than the limit, will always be encoded.
But I found problems when i want to inline a large size image into my entry jsbundle because this image is so important to my first screen rendering; Or when I don't want to inline trivial small images because there is no need to load them in time. I can't improve my page performance in this scene with url-loader
.
Now with img-optimize-loader
we can take more flexible control on this. We can specify every image whether or not to be encoded easily(using file query)regardless of limit
configuration. Still, if we don't specify it, limit
configuration will take control.
index.js
// Always let foo.png be encoded and inlined here regardless of 'limit configuration'
import encodedImage from './encode.png?__inline';
// Always emit real image file regardless of 'limit configuration'
import fileImage from './emit.png?__antiInline';
The query symbol __inline
and __antiInline
can be customed by your self.
The compression algorithm is based on imagemin. It supports images in png, jpg, gif, webp, svg format.
- minify JPEG image
- minify PNG image
- minify GIF image
- minify WEBP image
- minify SVG image
We support 3 levels for you to compress images automaticlly.
level | description |
---|---|
loseless | Only use lossless compress algorithm. Only support png/webp/svg images |
low | Cause a little distortion,and get small files. It will compress png/jpg/svg/gif images |
high | Cause more distortion,and get smaller files. It will compress png/jpg/svg/gif images |
To deal with webp images, please refer webp
webpack.config.js
module.exports = {
module: {
rules: [
{
test: /\.(png|jpe?g|webp|git|svg|)$/i,
use: [
{
loader: `img-optimize-loader`,
options: {
compress: {
// This will take more time and get smaller images.
mode: 'high', // 'lossless', 'low'
disableOnDevelopment: true,
},
},
},
],
},
],
},
};
And you can also adjust the compression manually using more params.
module.exports = {
module: {
rules: [
{
test: /\.(png|jpe?g|webp|git|svg|)$/i,
use: [
{
loader: 'img-optimize-loader',
options: {
compress: {
// loseless compression for png
optipng: {
optimizationLevel: 4,
},
// lossy compression for png. This will generate smaller file than optipng.
pngquant: {
quality: [0.2, 0.8],
},
// Compression for webp.
// You can also tranform jpg/png into webp.
webp: {
quality: 100,
},
// Compression for svg.
svgo: true,
// Compression for gif.
gifsicle: {
optimizationLevel: 3,
},
// Compression for jpg.
mozjpeg: {
progressive: true,
quality: 60,
},
},
},
},
],
},
],
},
};
When you enable compress.webp
, it will transform your png/jpg into webp files, and there will be no png/jpg files generated. Your source code will directly use webp file instead of png/jpg.
Generally, when you can use webp without incompatibility problem , there will be no need to use png or jpg any more, because webp files are always smaller than their png/jpg origin.
webpack.config.js
module.exports = {
module: {
rules: [
{
test: /\.(png|jpe?g|webp|git|svg|)$/i,
use: [
{
loader: `img-optimize-loader`,
options: {
compress: {
// This will transform your png/jpg into webp.
webp: true,
disableOnDevelopment: true,
},
},
},
],
},
],
},
};
Referer to webp configuration for details.
index.js
// This two images will be transformed into webp and your source code will use the webp format.
import encodedImage from './encode.png';
import fileImage from './test.jpg';
Type: [string]
Default: 'imgs/[contenthash].[ext]'
Specifies a custom filename template for the target images(s) using the query parameter name. For example, to emit a image from your context directory into the output directory retaining the full directory structure, you might use:
webpack.config.js
module.exports = {
module: {
rules: [
{
loader: `img-optimize-loader`,
options: {
name: '[path][name].[ext]',
},
},
],
},
};
Type: [Boolean]
Default: false
Decides js modules generated from image. Whether to use the ES modules or commonjs.
webpack.config.js
module.exports = {
module: {
rules: [
{
loader: `img-optimize-loader`,
options: {
esModule: false,
},
},
],
},
};
Type: String|Function
Default: undefined
Specify a filesystem path where the target file(s) will be placed.
webpack.config.js
module.exports = {
module: {
rules: [
{
test: /\.(png|jpe?g|gif)$/i,
loader: 'img-optimize-loader',
options: {
outputPath: 'images',
},
},
],
},
};
webpack.config.js
module.exports = {
module: {
rules: [
{
test: /\.(png|jpe?g|gif)$/i,
loader: 'img-optimize-loader',
options: {
outputPath: (url, resourcePath, context) => {
return `output_path/${url}`;
},
},
},
],
},
};
Type: String|Function
Default: __webpack_public_path__
+outputPath
Specifies a custom public path for the target file(s).
webpack.config.js
module.exports = {
module: {
rules: [
{
test: /\.(png|jpe?g|gif)$/i,
loader: 'img-optimize-loader',
options: {
publicPath: 'assets',
},
},
],
},
};
webpack.config.js
module.exports = {
module: {
rules: [
{
test: /\.(png|jpe?g|gif)$/i,
loader: 'img-optimize-loader',
options: {
publicPath: (url, resourcePath, context) => {
return `public_path/${url}`;
},
},
},
],
},
};
Type: String
Default: context
Specifies a custom file context.
Type: Boolean
Default: true
If true, emits a file (writes a file to the filesystem). If false, the loader will return a public URI but will not emit the file. It is often useful to disable this option for server-side packages.
Type: [String]
Default: __inline
Query symbol used to specify the image that should be encoded and inlined.
webpack.config.js
module.exports = {
module: {
rules: [
{
loader: `img-optimize-loader`,
options: {
inline: {
symbol: '__inline',
},
},
},
],
},
};
Type: [String]
Default: __antiInline
Query symbol used to specify the image that should not be encoded and inlined.
webpack.config.js
module.exports = {
module: {
rules: [
{
loader: `img-optimize-loader`,
options: {
inline: {
antiSymbol: '__antiInline',
},
},
},
],
},
};
Type: [Boolean|Number|String]
Default: 5000
A Number or String specifying the maximum size of a encoded image in bytes. If the image size is equal or greater than the limit file-loader
will be used (by default) and all query parameters are passed to it.
webpack.config.js
module.exports = {
module: {
rules: [
{
loader: `img-optimize-loader`,
options: {
inline: {
antiSymbol: '__antiInline',
},
},
},
],
},
};
Type: Boolean|String
Default: based from mime-types
Specify the mimetype
which the file will be inlined with.
If unspecified the mimetype
value will be used from mime-types.
The true
value allows to generation the mimetype
part from mime-types.
The false
value removes the mediatype
part from a Data URL (if omitted, defaults to text/plain;charset=US-ASCII
).
webpack.config.js
module.exports = {
module: {
rules: [
{
loader: `img-optimize-loader`,
options: {
inline: {
mimetype: false,
},
},
},
],
},
};
Sets the MIME type for the file to be transformed.
webpack.config.js
module.exports = {
module: {
rules: [
{
loader: `img-optimize-loader`,
options: {
inline: {
mimetype: 'image/png',
},
},
},
],
},
};
Type: Boolean|String
Default: base64
Specify the encoding
which the file will be inlined with.
If unspecified the encoding
will be base64
.
If you don't want to use any encoding you can set encoding
to false
however if you set it to true
it will use the default encoding base64
.
webpack.config.js
module.exports = {
module: {
rules: [
{
test: /\.svg$/i,
use: [
{
loader: `img-optimize-loader`,
options: {
inline: {
encoding: false,
},
},
},
],
},
],
},
};
It supports Node.js Buffers and Character Encodings which are ["utf8","utf16le","latin1","base64","hex","ascii","binary","ucs2"]
.
webpack.config.js
module.exports = {
module: {
rules: [
{
loader: `img-optimize-loader`,
options: {
inline: {
encoding: 'utf8',
},
},
},
],
},
};
Type: Function
Default: (mimetype, encoding, content, resourcePath) => mimetype;encoding,base64_content
You can create you own custom implementation for encoding data.
webpack.config.js
module.exports = {
module: {
rules: [
{
loader: `img-optimize-loader`,
options: {
inline: {
// The `mimetype` and `encoding` arguments will be obtained from your options
// The `resourcePath` argument is path to file.
generator: (content, mimetype, encoding, resourcePath) => {
if (/\.html$/i.test(resourcePath)) {
return `data:${mimetype},${content.toString()}`;
}
return `data:${mimetype}${
encoding ? `;${encoding}` : ''
},${content.toString(encoding)}`;
},
},
},
},
],
},
};
Type: string
Default: low
Specify the compress level.
level | description |
---|---|
loseless | Only use lossless compress algorithm. Only support png/webp/svg images |
low | Cause a little distortion,and get small files. It will compress png/jpg/svg/webp/gif images |
high | Cause more distortion,and get smaller files. It will compress png/jpg/svg/webp/gif images |
webpack.config.js
module.exports = {
module: {
rules: [
{
loader: `img-optimize-loader`,
options: {
compress: {
mode: 'high',
},
},
},
],
},
};
Type: [Object|Boolean]
Compress jpg images.
If you don't want to compress jpg files, you can set mozjpeg
to false
however if you set it to true
it will generator the settings according to compress.mode
configuration.
webpack.config.js
module.exports = {
module: {
rules: [
{
loader: `img-optimize-loader`,
options: {
compress: {
mozjpeg: false,
},
},
},
],
},
};
webpack.config.js
module.exports = {
module: {
rules: [
{
loader: `img-optimize-loader`,
options: {
compress: {
mozjpeg: {},
},
},
},
],
},
};
Link to mozjpeg configuration
Type: [Object|Boolean]
Compress png images.
If you don't want to use optipng to compress png files, you can set optipng
to false
however if you set it to true
it will generator the settings according to compress.mode
configuration.
webpack.config.js
module.exports = {
module: {
rules: [
{
loader: `img-optimize-loader`,
options: {
compress: {
optipng: false,
},
},
},
],
},
};
webpack.config.js
module.exports = {
module: {
rules: [
{
loader: `img-optimize-loader`,
options: {
compress: {
optipng: {},
},
},
},
],
},
};
Link to optipng configuration
Type: [Object|Boolean]
Compress png images.
If you don't want to use pngquant to compress png files, you can set pngquant
to false
however if you set it to true
it will generator the settings according to compress.mode
configuration.
webpack.config.js
module.exports = {
module: {
rules: [
{
loader: `img-optimize-loader`,
options: {
compress: {
pngquant: false,
},
},
},
],
},
};
webpack.config.js
module.exports = {
module: {
rules: [
{
loader: `img-optimize-loader`,
options: {
compress: {
pngquant: {},
},
},
},
],
},
};
Link to pngquant configuration
Type: [Object|Boolean]
Compress svg images.
If you don't want to compress svg files, you can set svgo
to false
however if you set it to true
it will generator the settings according to compress.mode
configuration.
webpack.config.js
module.exports = {
module: {
rules: [
{
loader: `img-optimize-loader`,
options: {
compress: {
svgo: false,
},
},
},
],
},
};
webpack.config.js
module.exports = {
module: {
rules: [
{
loader: `img-optimize-loader`,
options: {
compress: {
svgo: {},
},
},
},
],
},
};
Link to svgo configuration
Type: [Object|Boolean]
Compress gif images.
If you don't want to compress gif files, you can set gifsicle
to false
however if you set it to true
it will generator the settings according to compress.mode
configuration.
webpack.config.js
module.exports = {
module: {
rules: [
{
loader: `img-optimize-loader`,
options: {
compress: {
gifsicle: false,
},
},
},
],
},
};
webpack.config.js
module.exports = {
module: {
rules: [
{
loader: `img-optimize-loader`,
options: {
compress: {
gifsicle: {},
},
},
},
],
},
};
Type: [Object|Boolean]
Default: false
Transform png/jpg into webp. Compress webp files.
If you want to transform png/jpg into webp, you can set webp
to true
.
webpack.config.js
module.exports = {
module: {
rules: [
{
loader: `img-optimize-loader`,
options: {
compress: {
webp: true,
},
},
},
],
},
};
webpack.config.js
module.exports = {
module: {
rules: [
{
loader: `img-optimize-loader`,
options: {
compress: {
webp: {},
},
},
},
],
},
};
Link to webp configuration