Static asset caching

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

For a 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.
  • This also includes transformed images.
• 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.