Canonical tags: the most misunderstood 1 line of HTML
Why a single wrong canonical tag can silently cut your traffic in half
“Most canonical tag mistakes aren't wrong — they're just pointing at the wrong version of "right".”
A canonical tag looks like this:
It tells Google: "This is the real URL. If you find duplicates, credit this one."
The problem most sites have isn't missing canonical tags — it's canonical tags pointing to the wrong URL. The most common mistake: your canonical says www.yoursite.com but Google indexes yoursite.com. You've just told Google that your preferred URL is different from the one it's indexing. PageRank gets split. Rankings drop.
How to check yours: Open your homepage HTML, search for "canonical". Does the href match exactly what you see in your browser's address bar? If not — fix it.