Zinn® Cache Pro is a paid add-on to the free Zinn® Cache plugin. It installs on top of Zinn® Cache — it needs it, and does not replace it — and adds what a busy site needs to find and remove what is slowing it down. It is not included with Zinn® hosting: the free Zinn® Cache plugin is, and Pro is an optional upgrade for sites hosted with us or anywhere else.
Buying it, and the free trial
Open Zinn Digital® → Cache and choose the Pro tab. It lists what Pro adds and starts a free trial, with no card needed. Licences are annual, for one site, five sites or unlimited sites, and are sold, renewed and refunded through Freemius, which also delivers Pro's updates.
Turn on, in this order
- Cache analytics. Nothing to configure: look at the hit ratio after a day of traffic.
- The slow-query finder. It measures one page view in twenty and names the plugin or
theme behind each slow query, slow outside call and cache miss.
- The APCu tier, prefetching and compression, if the server has APCu and Redis. They make
each cached read cheaper and change nothing about what your pages show.
- Unused-CSS removal and delayed JavaScript — last, and one option at a time. These are
the only settings that can visibly change a page. Turn one on, load the site, then the next.
If the site looks broken after switching something on
Turn off delayed JavaScript and unused-CSS removal first — they are the cause the overwhelming majority of the time. Then purge everything and reload. Checkout, analytics and consent tools are left alone by default.
Cache health in your dashboard
On a site hosted with us, Pro reports its cache health to your dashboard every hour, and you are emailed when the hit ratio drops, Redis memory fills or keys start being evicted — once when it happens and once when it recovers.
Zinn® Cache Engine
The plugin that used this name before, Zinn® Cache Engine, was a standalone fork of LiteSpeed Cache for sites hosted elsewhere. It is retired: the free Zinn® Cache plugin now has a page cache that works on any server, and Zinn® Cache Pro is its add-on. If you still run Zinn® Cache Engine, install Zinn® Cache from WordPress.org, check the site, then deactivate and delete Zinn® Cache Engine.