Selective preload/early hints option

For the next version, I added support for WordPress’s wp_preload_resources hook. When third-party plugins use it, it will prioritize preloading the resources that were specifically called out with it, and also order them based on the fetchpriority attribute (if a plugin is calling out a specific resource to have a high priority it will be prioritized when building the preloading HTTP header).

As I mentioned before, I don’t have access to Perfmatter, so I’m not sure if they are leveraging that particular hook (although I would think they *should* be since it’s a mechanism that WordPress core gives them). Either way, the next version has support for better prioritization logic for sites that have plugins that use that hook.

Ya, I can’t control what Perfmatters does or doesn’t do. If Perfmatters isn’t leveraging WordPress’ wp_preload_resources hook to add it’s HTML-based preloading, then other things (for example this plugin) can’t extend that further to do things like feed them into the HTTP response headers. The next version will do that for anything using that hook, but I don’t have any control over if third-party plugins are doing it with the standard hooks WordPress gives them, or doing it their own (different) way.

Cloudflare intentionally does not use Early Hints when serving the page from cache because the HTTP response headers that build the Early Hints is in the response itself. Early Hints is most useful when you want to preload things, but you don’t have the ability to set what those are in the HTTP response headers. Doing Early Hints and then also a preload header would actually slow things down. For example, let’s say an HTML document is being served from Cloudflare’s cache (which includes the preload header). Doing early hints in that case is a waste of time and bandwidth because the preload header in the cached response is what Early Hints is trying to give the browser… so no need to do the first 103 Early Hints response because the info that’s giving you (what to preload) is already in the HTTP response headers for the normal cached request. Basically no need to ask what to preload before making the request because we already know the cached request is telling the browser what to preload before the first byte of the HTML is sent to the browser. That’s why Cloudflare doesn’t bother with Early Hints on a cached HTML page that has preload headers set (there’s no need to get that info twice before the first byte of the HTML is sent).

Being able to do preload info within HTTP response headers is always going to be better than doing them in the HTML source because the browser can start preloading them before it even starts to receive the HTML.

As far as ChatGPT stuff, I guess if it works for you, then great… but from the looks of it, ChatGPT is mistaken about some things… for example if you are using Cloudflare’s Cache Everything directive, you might want to revisit why you are doing that. That ends up causing more problems than it solves (for example serving cached content to logged in users). Additionally, inserting a Worker adds overhead and extra backend API requests to the underlying HTTP request. I’d definitely do some benchmarking with and without the inline Worker.

Again… Cloudflare intentionally does not do an Early Hint if it already knows the cached result *has* the same info that the Early Hint would yield within the HTTP response header. There simply isn’t a point because if the preload info is in the HTTP response header, the browser doesn’t need to receive that info twice (again, before the first byte of the HTML is received).

From the earlier page about Early Hints (basically it’s faster to not send Early Hints when it’s cached):

Early Hints may be emitted less frequently on requests where the content is cacheable. Cloudflare CDN is more likely to retrieve a response header before the asynchronous Early Hints lookup finishes if the response has been cached. Cloudflare will not send a 103 response if the main response header is already available.

https://developers.cloudflare.com/cache/advanced-configuration/early-hints/

• This reply was modified 6 months, 3 weeks ago by digitalpoint.