PageSpeed will make a best effort to expire its asset (.css, .js, .png, .gif, .jpg) cache periodically. During periods of rapid changes, automatic expunction may lag behind changes pushed to a server necessitating a manual flush of the cache.
Expunging PageSpeed cache
A PURGE header may be sent to the asset forcing PageSpeed to expunge its cached copy from memory. For example to accomplish this using cURL from the terminal:
curl -v -X PURGE http://web.site/asset/style.css
To expunge every entry under a common URL or on a web site, use an asterisk:
curl -v -X PURGE http://web.site/asset/*
See also
- Flushing PageSpeed Server-Side Cache (developers.google.com)