Categories and tags cause so much confusion in WordPress. They get out of control, and can wreck the SEO of your site.
When for smaller sites you can just completely forget about tags.
WordPress tags are to help classify your content. They add a second layer of classification after categories.
And this is a critical thing that people get wrong with tags. Categories should always be the main way you group similar content together. Tags then refine those groupings into sub-groups or provide useful alternative paths to find related content. The key here being useful, as in useful to a real person.
If you’re peppering every blog post with a dozen tags in the belief it will make your post rank better in Google, please stop. 🙂
When you add a tag to a WordPress post two things happen.
Firstly that tag will appear somewhere on the blog post, usually at the bottom as a link. This links to a ‘tag page’ (same as a category page but for tags).
Secondly that post will now appear on that tag page. For each tag you added.
So Google and Bing etc will see a link (‘My Useful Tag’) and follow that link to find out what’s on that page. Just the same as any other internal link on your site.
When they visit the page they will typically see a page that looks just like a category page (depending on the theme your site is using, and/or how it’s been designed). But Google doesn’t care if this is a tag page or a category page. They don’t even care if you made the page with WordPress or handcoded it in Notepad like it’s 1996.
What matters is what’s on the page, and how useful that is.
If a tag helps people find more content they want to read, then it’s useful. That’s your measure.
Not meeting some crazy “I must add 5-10 tags to every post for SEO” requirement that somebody dreamt up last decade. Stop doing that.
On larger sites tag pages can even become rich content hub pages that pull in content beyond just a list of posts. They can become valuable pages in their own right that get Google search traffic.
But tags become particularly unhelpful (useless!) in two different ways:
When tags are too general or too specific they are potentially harmful to SEO.
If a tag is too general it can end up creating duplicate content. This can happen where tags are so general they end up being the same as a category or other taxonomy (e.g. author pages or even date based archives).
We’ve even seen sites where a particular tag is applied to every single post – creating tag pages that duplicate the entire main blog feed (‘blog home’).
If a tag is too specific however it may only apply to a few posts. This creates a tag page with very little content on it. Worst case, and we see this a lot, a tag page with just the one post on it! Clearly that’s not useful to anyone – they click the tag to find more content on that subject only to discover there isn’t any more.
The danger is that Google rightly considers this to be ‘thin content’ (i.e. content of very little value to anyone, and therefore a low quality page). And if you give Google too many low quality pages compared to high quality pages then it can affect how they see the overall quality of your site, leading to a drop for the entire site in the search results.
Be very aware that adding a new tag will create a new page in your site. A page that will be low quality and of no value unless you do something more to elevate it.
You can make it better quality by immediately tagging relevant older posts with that new tag. Then gradually making the page more useful over time as newer content is added.
Or another way to think of this is to never create a new tag until you have enough content to make creating that tag page worthwhile. Don’t just blindly create tags as part of creating a post.
WordPress sites don’t need tags. They don’t really work in the same way that tags on social media platforms work.
If your site has only a couple of hundred posts then it’s unlikely that tags will add any benefit at all. Look at your categories again first before starting to use tags. And then also consider subcategories.
If your site has thousands of posts then you’re hitting the territory where tags can be useful. But again, we’re talking ‘useful’ as in useful to people. If you add those tags will people use them? Will they click on those tag links at the end of the post to find more content on that specific topic? Or would a category link here be just as useful? Or a ‘related posts’ section?
One of the many things that Google tracks is what people click on when they are using your site. (How can they possibly know that..? There’s a reason Google created the Chrome web browser, which is now used by around 65% of all web users!). So Google can get a good understanding of what is and isn’t useful on your site, and they will attribute more or less value based on that.
We’ve worked with sites that have quite literally many thousands of tags that never get clicked on. Which have zero value to real people. But provide Google with many thousands of low quality ‘thin content’ pages that were dragging down SEO performance.
Another problem with ‘out of control’ tagging is that it can lead to what we call tag cannibalisation. Effectively tags competing with each other and even other page types too.
Avoid these tagging mistakes:
Subcategories are less well known in WordPress, but are easy to create – you just select a ‘Parent Category’ from the dropdown menu when you create the Category.
I would encourage you to explore subcategories as an option first before unleashing tags on your site. Particularly as one of the key differences between tags and categories is that tags do not have a heirarchy (there is no such thing in WordPress as a ‘subtag’).
[Also see How to Fix SEO Problems When Adding WordPress Posts to Multiple Categories]
A subcategory does not make sense in every case but there is some overlap where you could use either a tag or a subcategory and it would be fine.
In most cases, no tags at all is the best answer.
But where tags have become useful because of the size of the site, then the answer really is ‘as many as are useful and no more’.
It’s perfectly possible for a site to have 10’s of thousands of posts but for tags to be useless in that specific case. It really does depend on your content and doing the best to help your users navigate it.
Thankfully, doing the best thing for SEO with tags now ‘just happens’ as a result of doing the right thing for people.
If you need help taming a tag nightmare please do get in touch. Technical SEO is one of our specialities so cleaning up problems caused by runaway tagging and wayward categories is something we come across regularly.