Need Help Configuring Cache Timeout & Preloading

Hi @sbdermaceuticals,

Thanks for the detailed post; you’re on the right track with your setup. Here’s a breakdown of your key questions:

Static Assets Not Being Cached

WP Super Cache mainly caches full-page HTML, not individual files like CSS, JS, or images, so this is expected behavior. To improve the delivery of those static assets, consider enabling a dedicated CDN.

Image Loading Issues

The image delays you’re seeing are typically caused by large file sizes or lack of compression, not by page cache settings. As noted above, we recommend installing an image optimization plugin to optimize images and serve faster formats like WebP.

Should You Enable Preload?

With over 1,200 products, this can be resource-intensive, but if your hosting is solid, it’s worth testing. You don’t need to delete the full cache weekly. With preload mode enabled, portions of the cache will be cleared/deleted when posts are modified.

Hope this was helpful! Please let us know if you need further assistance or if you have additional questions.

Hello @sbdermaceuticals

 I also wondered if a plugin that defers and/or concentrates css and js would help but I’m not sure if such a plugin would be compatible with WP Super Cache…..

I had a feeling we need an Image optimization plugin to improve things. Are there any recommendations that are compatible with WP Super Cache?

Depending on the exact nature of your site’ content, Jetpack’s Site Accelerator and Jetpack Boost, which are maintained by the same developers working on WP Super Cache, may be an option as long as the material does not violate our service guidelines regarding explicit content.

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Regarding your cache timeout settings, there’s no universal “perfect” number. For a site that updates weekly, a longer cache timeout is reasonable. You can experiment with gradually increasing that value to see what works best for your site.

For preloading and garbage collection, yes, you can disable garbage collection, and is encouraged in our documentation. That said, if you ever encounter storage or performance issues, you can adjust these settings further.

Hope this was helpful! Please let us know if you need further assistance or if you have additional questions.

Hi @sbdermaceuticals,

Yes, setting WP Super Cache’s timeout to a week is reasonable for static pages. Nonces (used in forms, carts, etc.) expire after 12 – 24 hours, so caching those pages longer can cause errors.

Best approach:

• For static pages: a week is fine.
• For dynamic pages: keep cache timeout under 12 hours or exclude those pages via “Rejected URL Strings” in WP Super Cache settings.

Also, while experimenting with an ideal number, just watch for issues on any interactive pages.

Best,

Hey @sbdermaceuticals,

Those settings are probably generally safe on a dedicated server, but with a very long cache timeout (several days), the main concern is that cached files will pile up and only be cleaned after they’re expired. Also, with long timeouts, if your site contains a huge number of cache files, the garbage collection process could cause a bit of server strain as it scans and deletes expired cache files.

Things to watch for and consider:

• If you notice load spikes or slowdowns, consider reducing the cache timeout (so fewer files accumulate before expiry) or increasing the frequency of garbage collection (making the interval smaller, like 1/12 or 1/24 the timeout)
• If cache files are not expiring often, infrequent garbage collection is fine, but if your site updates a lot, more frequent garbage collection helps keep content fresh for visitors

Please let us know if you have any other questions. Cheers!

Hey again, @sbdermaceuticals! Our pleasure.

I’ll go ahead and mark this as resolved now, but please do reach out in the future whenever you need us.