Static asset caching

Static assets for WordPress and Node.js environments are cached and served by VIP’s edge cache servers.

For static asset file that is deployed from the application’s wpcomvip GitHub repository: The actual default time to live (TTL) for the cached version of the cached version of the file is:

• 15 days for enqueued JS and CSS files that are concatenated by VIP (identifiable by request paths that begin with /_static/??).
• 1 year for static asset files that are served by the web application server and have file extensions: jp(e)g, .gif, .png, .swf, .css, .js, .manifest, opensearch.xml, .webm, .webp, .svg, .ico, .ieot, .ttf, .otf, .woff2
• The cache for a static asset file located within an environment’s deploying branch is automatically cleared upon a code deployment if it includes an updated version of that file.

For a media file that was uploaded or imported to the VIP File System (located within /wp-content/uploads): The actual default TTL for the cached version of the file is 1 year.

Browser caching

By default, the Cache-Control HTTP header for static files is set to cache-control: max-age=31536000 (1 year). The value of this header (e.g. max-age or s-maxage) can be modified for static assets that are served by the origin application web server but not for files that are stored in the VIP File System.