A short guide to canonical URLs

There is no clever trick in this one, just a handful of decisions worth making deliberately. Everything we would tell a client about canonical URLs in the time it takes to drink a coffee.

Search work compounds slowly, which is why it gets abandoned about two months before it would have paid off. If two people in the business would answer this differently, that gap is the actual problem.

Why this earns attention

Canonicals tell search engines which version is the real one. Where this goes wrong is almost never a lack of knowledge. Check it against what you would want a competitor's site to get wrong.

How we handle it

Parameters and print views create duplicates quietly. In practice this is a scheduling problem more than a technical one. If it only works because one person remembers to do something, it does not work yet.

What to watch for

Self-referencing canonicals are a safe default. The cost of getting this wrong is rarely visible on the day it happens. If two people in the business would answer this differently, that gap is the actual problem.

The short version

Search engines are trying to answer a question, so the pages that answer questions clearly tend to do well. Three things worth confirming about canonical URLs before you move on:

• Someone can say what the current setup is without going to look
• Canonicals tell search engines which version is the real one — and you know whether that is true here
• There is a way to tell whether the last change to this helped

Pick the one that would hurt most if it failed, and start there.