Note: this feature is available with
[email protected]and higher.
Changing the HTML
public folder contains the HTML file so you can tweak it, for example, to set the page title.
<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
Note that we normally encourage you to
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 an environment variable called
index.html, you can use it like this:
Only files inside the
public folder will be accessible by
%PUBLIC_URL% prefix. If you need to use a file from
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.
process.env.PUBLIC_URL for similar purposes:
Keep in mind the downsides of this approach:
- None of the files in
publicfolder 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
- You need a file with a specific name in the build output, such as
- You have thousands of images and need to dynamically reference their paths.
- You want to include a small script like
pace.jsoutside of the bundled code.
- Some libraries may be incompatible with webpack and you have no other option but to include it as a
Note that if you add a
<script> that declares global variables, you should read the topic Using Global Variables in the next section which explains how to reference them.