Almost everything I’ve read says that you should run a caching plugin on a WordPress site, but there isn’t much agreement on which one. I’m currently using WP Super Cache but I have no idea if it actually helps or even if I have it configured correctly.
Any thoughts on whether to use a cache and if so, which one?
They definitely help. For less popular sites it can be somewhat insignificant, however I’ve always taken the approach that even a second or two minimized in load time isn’t ever a bad thing. As for which one, there are two I like:
WP Super Cache is my “set it and forget it” one. If someone just wants to have a low level cache turned on that does the job without a lot of fanfare that’s the one to go for. Install, Activate, and turn on caching and you’re done. Also has the benefit of rarely if ever breaking websites. Plus it’s made by the same people that make WordPress so that has to count for something, right?
W3 Total Cache is great for someone on the opposite end of the spectrum that knows what they’re doing and wants full control over how the caching is done. It can work with content delivery networks like Cloudflare and Amazon Cloudfront. It can minify javascript and CSS assets. It can serve from Memcache or Varnish servers. There are tons of options (90% of which are complete jargon, but if you know what you’re doing they’re powerful). I used it recently on a site and saw significant performance gains, but the tradeoff there is there is a steep learning curve and this one does have the potential of breaking a site if you get the settings wrong so it’s very much not set it and forget it.
Those are the two I keep in my playbook depending on the use case but typically favor and recommend the first for the reasons outlined.