How to get render-blocking resources right

This is one of those topics that looks small until it costs you something. The short answer to render-blocking resources is that it is mostly a sequence of small decisions, not one big one.

Real-world numbers from actual visitors matter more than a score produced on a fast laptop. The teams that stay on top of it are the ones who put it on a calendar rather than a wish list.

Why this earns attention

Scripts and styles in the head delay the first paint. It is worth being explicit about, because assumptions differ quietly. It is the sort of thing that looks like polish right up until it costs you an enquiry.

The steps

1. Establish what you have today before changing anything
2. Defer anything that is not needed immediately
3. Third-party tags are frequent offenders
4. Write down the decision so the next person does not re-litigate it

Third-party tags are frequent offenders. None of that requires a large budget, only a decision and someone to own it. The version that survives contact with a real deadline is the simple one.

A reasonable first step

What this looks like day to day

Speed is a feature people notice only in its absence, and then they leave rather than complain. Three things worth confirming about render-blocking resources before you move on:

• Someone can say what the current setup is without going to look
• Third-party tags are frequent offenders — and you know whether that is true here
• There is a way to tell whether the last change to this helped

Worth checking on your own setup before it becomes someone else's problem to fix.