Before you invest in performance budgets

Every audit we run turns up some version of this. Before you spend anything on performance budgets, it is worth confirming a few things are already true.

Speed is a feature people notice only in its absence, and then they leave rather than complain. Doing this properly once is usually cheaper than doing it approximately three times.

Prerequisites

• You can describe the outcome you want in one sentence
• Someone owns it after the work is done
• A number in writing stops slow creep
• You have a way to tell whether it worked

Where it usually goes wrong

Budget for total page weight and script size. The teams that handle this well are rarely the ones with the biggest budgets. The teams that stay on top of it are the ones who put it on a calendar rather than a wish list.

Enforce it automatically or it gets ignored. There is a version of this that is over-engineered, and it is worth avoiding. If it only works because one person remembers to do something, it does not work yet.

What this looks like day to day

Real-world numbers from actual visitors matter more than a score produced on a fast laptop. Three things worth confirming about performance budgets before you move on:

• Someone can say what the current setup is without going to look
• Budget for total page weight and script size — 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.