Using the Public Folder
Note: this feature is available with
react-scripts@0.5.0
and higher.
Changing the HTML
The public
folder contains the HTML file so you can tweak it, for example, to set the page title.The <script>
tag with the compiled code will be added to it automatically during the build process.
Adding Assets Outside of the Module System
You can also add other assets to the public
folder.
Note that we normally encourage you to import
assets in JavaScript files instead.For example, see the sections on adding a stylesheet and adding images and fonts.This mechanism provides a number of benefits:
- Scripts and stylesheets get minified and bundled together to avoid extra network requests.
- Missing files cause compilation errors instead of 404 errors for your users.
- Result filenames include content hashes so you don’t need to worry about browsers caching their old versions.However there is an escape hatch that you can use to add an asset outside of the module system.
If you put a file into the public
folder, it will not be processed by Webpack. Instead it will be copied into the build folder untouched. To reference assets in the public
folder, you need to use a special variable called PUBLIC_URL
.
Inside index.html
, you can use it like this:
<link rel="shortcut icon" href="%PUBLIC_URL%/favicon.ico">
Only files inside the public
folder will be accessible by %PUBLIC_URL%
prefix. If you need to use a file from src
or node_modules
, you’ll have to copy it there to explicitly specify your intention to make this file a part of the build.
When you run npm run build
, Create React App will substitute %PUBLIC_URL%
with a correct absolute path so your project works even if you use client-side routing or host it at a non-root URL.
In JavaScript code, you can use process.env.PUBLIC_URL
for similar purposes:
render() {
// Note: this is an escape hatch and should be used sparingly!
// Normally we recommend using `import` for getting asset URLs
// as described in “Adding Images and Fonts” above this section.
return <img src={process.env.PUBLIC_URL + '/img/logo.png'} />;
}
Keep in mind the downsides of this approach:
- None of the files in
public
folder get post-processed or minified. - Missing files will not be called at compilation time, and will cause 404 errors for your users.
- Result filenames won’t include content hashes so you’ll need to add query arguments or rename them every time they change.
When to Use the public Folder
Normally we recommend importing stylesheets, images, and fonts from JavaScript.The public
folder is useful as a workaround for a number of less common cases:
- You need a file with a specific name in the build output, such as
manifest.webmanifest
. - You have thousands of images and need to dynamically reference their paths.
- You want to include a small script like
pace.js
outside of the bundled code. - Some library may be incompatible with Webpack and you have no other option but to include it as a
<script>
tag.Note that if you add a<script>
that declares global variables, you also need to read the next section on using them.