To use Swift caching plugin, you must install it. Go to WP admin > Add Plugins > search “Swift Performance”, install and activate.
Go into Swift settings, click [Advanced View] on the right side. Then set as follows. (NOTE: if I don’t mention a certain item, that means leave it on default! Some items are only in the paid version.):
- General > General – enable “Use Compute API” if you have it.
- General > Tweaks – check “Normalize Static Resources”, and put your 301 HTTPS redirects (use method #2) in the “Custom Htaccess” section.
- Media > Images – everything off except for “Keep Original Images”.
- Optimization > General – everything OFF! Enable “Limit Simultaneous Threads” and set “Maximum Threads” to 3.
- Optimization > Scripts – disable “Merge Scripts”!
- Optimization > Styles – disable “Merge Styles”!
- Caching > General – Enable Caching, Early Loader, Enable Browser Cache, Enable GZIP…all of these should be ON. Caching Mode should be “Disk Cache with Rewrites”.
- Caching > Tweaks – doesn’t matter.
- Caching > Exceptions – for “Exclude Post Types”, I usually exclude everything except for pages, posts, products and any other types of items that have their own URL on front-end. For “Exclude Pages”, I usually exclude any pages with contact forms if you have issues with them. Login/Cart/Checkout/Account pages are also good candidates for exclusion. At the bottom, leave “Exclude Archive” to OFF.
- Caching > Warmup – Prebuild Cache Automatically, Prebuild Author Pages, Prebuild Archive…should all be ON. Everything else OFF. Prebuild Speed should be either Unlimited or Moderate (for sites with thousands of pages).
- Caching > Varnish – we don’t have Varnish. Leave it OFF.
- CDN > General – if you have CDN, turn on “Enable CDN” and “Enable CDN on SSL” and enter your CDN hostname here (usually a subdomain like “cdn.domain.com”). Leave everything else alone. Do not enable CDN here if you only have Cloudflare.
- CDN > Cloudflare – check “Enable Auto Purge” and then enter your Cloudflare account email and API key.
For a more detailed explanation of all the options, read this UNOFFICIAL Swift Performance Cache Guide.