# Simple cache busting with Nginx

You update your `app.js` or `styles.css`, but have a caching of 30 days and none of the clients will get the latest version? 😟

While the best would be to use a build mechanism to generate new filenames on the server, here is how to ensure clients get your last updates:

**1\.** Change the name of the files in the HTML, for example `styles.css` to `styles.123.css`

**2\.** Add this cache busting snippet in your nginx conf:
```nginx
location ~* (.+)\.(?:\d+)\.(js|css)$ {
  try_files $uri $1.$2;
}
```

The browser won’t know this new CSS file, and so will download it. And nginx will transparently return the right file.