A short guide to response compression

It is rarely the thing that gets a project approved, and often the thing that decides how it goes. Everything we would tell a client about response compression in the time it takes to drink a coffee.

Real-world numbers from actual visitors matter more than a score produced on a fast laptop. Anything you cannot measure here, you are deciding by taste, which is fine as long as everyone knows it.

What it costs to ignore

Text compresses dramatically and costs almost nothing to enable. 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.

How we handle it

Modern algorithms beat older ones by a useful margin. It is worth being explicit about, because assumptions differ quietly. The failure mode is not doing it wrong, it is doing it once and assuming it stays done.

Common failure modes

Already-compressed formats gain nothing from it. In practice this is a scheduling problem more than a technical one. It is the sort of thing that looks like polish right up until it costs you an enquiry.

In practice

Performance work is mostly subtraction, which makes it unpopular and effective. Three things worth confirming about response compression before you move on:

• Someone can say what the current setup is without going to look
• Text compresses dramatically and costs almost nothing to enable — 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.