file-loader
The file-loader
resolves import
/require()
on a file into a url and emits the file into the output directory.
Getting Started
To begin, you'll need to install file-loader
:
$ npm install file-loader --save-dev
Import (or require
) the target file(s) in one of the bundle's files:
file.js
import img from './file.png';
Then add the loader to your webpack
config. For example:
webpack.config.js
module.exports = {
module: {
rules: [
{
test: /\.(png|jpg|gif)$/,
use: [
{
loader: 'file-loader',
options: {},
},
],
},
],
},
};
And run webpack
via your preferred method. This will emit file.png
as a file
in the output directory (with the specified naming convention, if options are
specified to do so) and returns the public URI of the file.
️ By default the filename of the resulting file is the hash of the file's contents with the original extension of the required resource.
Options
name
Type: String|Function
Default: '[hash].[ext]'
Specifies a custom filename template for the target file(s) using the query
parameter name
. For example, to emit a file from your context
directory into
the output directory retaining the full directory structure, you might use:
String
webpack.config.js
module.exports = {
module: {
rules: [
{
test: /\.(png|jpg|gif)$/,
loader: 'file-loader',
options: {
name: '[path][name].[ext]',
},
},
],
},
};
Function
webpack.config.js
module.exports = {
module: {
rules: [
{
test: /\.(png|jpg|gif)$/,
loader: 'file-loader',
options: {
name(file) {
if (process.env.NODE_ENV === 'development') {
return '[path][name].[ext]';
}
return '[hash].[ext]';
},
},
},
],
},
};
️ By default the path and name you specify will output the file in that same directory, and will also use the same URI path to access the file.
outputPath
Type: String|Function
Default: undefined
Specify a filesystem path where the target file(s) will be placed.
String
webpack.config.js
module.exports = {
module: {
rules: [
{
test: /\.(png|jpg|gif)$/,
loader: 'file-loader',
options: {
outputPath: 'images',
},
},
],
},
};
Function
webpack.config.js
module.exports = {
module: {
rules: [
{
test: /\.(png|jpg|gif)$/,
loader: 'file-loader',
options: {
outputPath: (url, resourcePath, context) => {
// `resourcePath` is original absolute path to asset
// `context` is directory where stored asset (`rootContext`) or `context` option
// To get relative path you can use
// const relativePath = path.relative(context, resourcePath);
if (/my-custom-image\.png/.test(resourcePath)) {
return `other_output_path/${url}`;
}
if (/images/.test(context)) {
return `image_output_path/${url}`;
}
return `output_path/${url}`;
},
},
},
],
},
};
publicPath
Type: String|Function
Default: __webpack_public_path__
Specifies a custom public path for the target file(s).
String
webpack.config.js
module.exports = {
module: {
rules: [
{
test: /\.(png|jpg|gif)$/,
loader: 'file-loader',
options: {
publicPath: 'assets',
},
},
],
},
};
Function
webpack.config.js
module.exports = {
module: {
rules: [
{
test: /\.(png|jpg|gif)$/,
loader: 'file-loader',
options: {
publicPath: (url, resourcePath, context) => {
// `resourcePath` is original absolute path to asset
// `context` is directory where stored asset (`rootContext`) or `context` option
// To get relative path you can use
// const relativePath = path.relative(context, resourcePath);
if (/my-custom-image\.png/.test(resourcePath)) {
return `other_public_path/${url}`;
}
if (/images/.test(context)) {
return `image_output_path/${url}`;
}
return `public_path/${url}`;
},
},
},
],
},
};
context
Type: String
Default: context
Specifies a custom file context.
module.exports = {
module: {
rules: [
{
test: /\.(png|jpg|gif)$/,
loader: 'file-loader',
options: {
context: 'project',
},
},
],
},
};
emitFile
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.
file.js
// bundle file
import img from './file.png';
webpack.config.js
module.exports = {
module: {
rules: [
{
test: /\.css$/,
loader: 'file-loader',
options: {
emitFile: false,
},
},
],
},
};
regExp
Type: RegExp
Default: undefined
Specifies a Regular Expression to one or many parts of the target file path.
The capture groups can be reused in the name
property using [N]
placeholder.
file.js
import img from './customer01/file.png';
webpack.config.js
module.exports = {
module: {
rules: [
{
test: /\.(png|jpg|gif)$/,
loader: 'file-loader',
options: {
regExp: /\/([a-z0-9]+)\/[a-z0-9]+\.png$/,
name: '[1]-[name].[ext]',
},
},
],
},
};
️ If [0]
is used, it will be replaced by the entire tested string, whereas[1]
will contain the first capturing parenthesis of your regex and so on...
Placeholders
Full information about placeholders you can find here.
[ext]
Type: String
Default: file.extname
The file extension of the target file/resource.
[name]
Type: String
Default: file.basename
The basename of the file/resource.
[path]
Type: String
Default: file.directory
The path of the resource relative to the webpack/config context
.
[folder]
Type: String
Default: file.folder
The folder of the resource is in.
[emoji]
Type: String
Default: undefined
A random emoji representation of content
.
[emoji:<length>]
Type: String
Default: undefined
Same as above, but with a customizable number of emojis
[hash]
Type: String
Default: md5
Specifies the hash method to use for hashing the file content.
[<hashType>:hash:<digestType>:<length>]
Type: String
The hash of options.content (Buffer) (by default it's the hex digest of the hash).
digestType
Type: String
Default: 'hex'
The digest that the hash function should use. Valid values include: base26, base32, base36, base49, base52, base58, base62, base64, and hex.
hashType
Type: String
Default: 'md5'
The type of hash that the has function should use. Valid values include: md5
,
sha1
, sha256
, and sha512
.
length
Type: Number
Default: undefined
Users may also specify a length for the computed hash.
[N]
Type: String
Default: undefined
The n-th match obtained from matching the current file name against the regExp
.
Examples
The following examples show how one might use file-loader
and what the result would be.
file.js
import png from './image.png';
webpack.config.js
module.exports = {
module: {
rules: [
{
test: /\.(png|jpg|gif)$/,
loader: 'file-loader',
options: {
name: 'dirname/[hash].[ext]',
},
},
],
},
};
Result:
# result
dirname/0dcbbaa701328ae351f.png
file.js
import png from './image.png';
webpack.config.js
module.exports = {
module: {
rules: [
{
test: /\.(png|jpg|gif)$/,
loader: 'file-loader',
options: {
name: '[sha512:hash:base64:7].[ext]',
},
},
],
},
};
Result:
# result
gdyb21L.png
file.js
import png from './path/to/file.png';
webpack.config.js
module.exports = {
module: {
rules: [
{
test: /\.(png|jpg|gif)$/,
loader: 'file-loader',
options: {
name: '[path][name].[ext]?[hash]',
},
},
],
},
};
Result:
# result
path/to/file.png?e43b20c069c4a01867c31e98cbce33c9
Contributing
Please take a moment to read our contributing guidelines if you haven't yet done so.