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Check Cache-Control of all CSS, JS and image files on a page

harmlessImages and performancedebian, ubuntu
Adjust the values, the command updates live
user@server
curl -s https://example.com/ | grep -oE '(src|href)="[^"]+\.(css|js|woff2?|jpe?g|png|gif|webp|avif|svg)(\?[^"]*)?"' | cut -d'"' -f2 | sed -E 's#^//#https://#; s#^/#https://example.com/#' | grep '^http' | sort -u | while read -r a; do printf '%-45s %s\n' "$(curl -sI "$a" | grep -i '^cache-control:' | tr -d '\r')" "$a"; done

Extracts stylesheets, scripts, fonts and images from the HTML, turns root-relative paths into absolute URLs and requests the Cache-Control header for each file. Static assets should be cached for a long time (a max-age of one year for versioned files). An empty left column means no Cache-Control is set.

Note: Relative paths without a leading slash and files loaded via CSS or JavaScript are missed. The entry on browser caching headers in the nginx category checks individual URLs.

Also searched as

  • check browser caching for all assets
  • show cache headers of css and js files
  • serve static assets with an efficient cache policy
  • which files are not cached

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