How to get canonical URLs right
This is cheap to get right at the start and expensive to retrofit. The short answer to canonical URLs is that it is mostly a sequence of small decisions, not one big one.
Search engines are trying to answer a question, so the pages that answer questions clearly tend to do well. It is worth deciding this deliberately rather than inheriting whatever the last person set up.
The reason this keeps coming up
Canonicals tell search engines which version is the real one. The reasoning matters more than the rule, because the rule has exceptions. Budget a little time for it every quarter and it never becomes a project of its own.
The steps
- Establish what you have today before changing anything
- Parameters and print views create duplicates quietly
- Self-referencing canonicals are a safe default
- Write down the decision so the next person does not re-litigate it
Self-referencing canonicals are a safe default. Where this goes wrong is almost never a lack of knowledge. The version that survives contact with a real deadline is the simple one.
Making it stick
How to tell if yours is fine
Technical fixes remove obstacles; content earns the position. Both are needed and they are not interchangeable. Three things worth confirming about canonical URLs before you move on:
- Someone can say what the current setup is without going to look
- Self-referencing canonicals are a safe default — 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.