What is a canonical tag, when should you use it, and which pages on a site need it?

When duplicate content occurs: 1) URL parameters (sort, filter, color). 2) Protocol (http vs https). 3) Domain (www vs non-www). 4) Trailing slash (/page vs /page/). 5) Session ID. If any of these create duplicates add a canonical.

On product pages: /tshirt?color=red > canonical /tshirt. If the color option is important (it changes the title), set the canonical to the parameter version.

we didn't have canonicals at first, had lots of parameers (filter sort etc.). honestly google was crawling through duplicate pages. once we added canonicals pointing all parameters to the base URL, Google's crawl speed increased.

impact: 2 weeks ater adding canonicals the sites 'indexed' page count dropped by 40% — copies arent counted, only originals are. we saw a +2-3 rank improvement on some pages.

canonical tag basically means: you're telling google 'which one is the original of this page', so when you write canonical, google counts that as the main one... even if woordpress does it automatically, check it.

Canonical: Youre telling Google 'hey, I have lots of copies, this one is the original'. Google: ok marked it. anyway doesnt waste crawl budget, focuses on the original.

If you have duplicate URL parameters, set the canonical to the base URL. Pick one for WWW vs non-WWW. If it's WordPress, Yoast handles this.

I'll try it.

If you're going this route, sort this out first. Everything goes well for the first three months; problems arise in the fourth.

Everyone rushing into canonical tag gets stuck at the same point.

Let me share my experience. Don't hesitate to ask; those who don't ask always pay more.

Hope this helps.

Sorry, but this doesn't apply in every case. Everything goes well for the first three months; problems arise in the fourth.

Hope this helps.

Great work. If it's your first time, start small; scaling comes later.

Hasty decisions become decisions you have to fix six months later. I'm also curious if anyone does it differently.

Great work.

The most overlooked point about canonical tag is this: If you don't write this down from the start, it leads to arguments later.

let me summarize the topic, since several different answers were given and updating an existing page yields faster results than creating a new one.

discussing numbers without verifying the measureent setup is a waste of time.

I'd appreciate it if you shared the outcome. When you try to change everything at once, nothing settles.

This is my opinion, I'm not claiming it's absolute truth.

i was thinking the same thing. when you try to change everything at once, nothing settles.

proven by experience.

Let me share my experience. Discussing numbers without verifying the measurement setup is a waste of time.

Correct me if I'm wrong.

I agree.

Let me summarize the topic, since several different answers were given. When making a decision, first look at what data you have on hand.