Categories or Tags: How to Organise a Blog

Short answer: categories are the few broad sections of your blog, like chapters; every post belongs to one, occasionally two. Tags are specific topics that cut across sections, like an index; a post might have two to four. Keep categories to five to eight and never create a tag you will use only once. Archive pages for both are real pages that search engines can index, so each indexable archive should have a short description and enough posts to be worth landing on. Archives that are thin or duplicate belong on noindex.

WordPress gives every blog two ways to group posts, and most blogs use them interchangeably, which is how you end up with a category called SEO, a tag called seo, another tag called SEO tips, and three archive pages that list roughly the same posts.

The two have different jobs. Using each for its job makes the site easier to navigate and removes a surprising amount of duplicate content.

Categories are sections

Think of categories as the sections of a magazine or the chapters of a book. A reader should understand the whole blog by reading the list of them.

Five to eight is right for most sites. Each should be broad enough to hold dozens of posts over time. Every post belongs to one; two is acceptable occasionally; more than two means the categories are too narrow.

Category names should be words your readers use, not internal labels. Guides and How-to is clearer than Resources, and Pricing and Plans is clearer than Commercial.

Tags are the index

Tags are specific topics that cross sections. An article on meta descriptions might sit in the SEO category and carry the tags meta-descriptions and search-console.

The rules that keep tags useful:

• Two to four per post. More than that and they stop meaning anything.
• Never a tag used once. A tag with one post is an archive page that duplicates that post.
• One form per concept. Decide singular or plural, and pick one spelling.
• No tag that repeats a category name. That is two archives listing the same posts.

A blog with 200 posts might reasonably have 30 to 60 tags. A blog with 200 posts and 400 tags has a problem.

Archive pages are real pages

Every category and tag creates an archive page: a URL listing its posts. Search engines crawl these and may index them, and readers do land on them.

An indexable archive should have a short description at the top — a few sentences saying what the section covers and who it is for. Without one, it is a list of links with no content of its own, and it is the page most likely to be judged thin.

Writing archive descriptions

Five to seven sentences is enough for a tag or category description. It should say what the topic is, what the reader will find, and what questions the posts answer.

It is also a small piece of genuinely useful content: the page a reader lands on when they want everything you have written on a subject. Treat it like a short introduction rather than a keyword field.

On this blog every tag carries a description of that length, which is part of why the tag pages are worth visiting rather than bare lists.

Fixing an overgrown system

If the blog already has hundreds of tags, cleaning up is worth an afternoon.

1. Export the list with the post count for each.
2. Group duplicates — spelling variants, singular and plural, synonyms.
3. Merge each group into one tag. WordPress can reassign posts; redirect the old archive URL to the survivor.
4. Set noindex on tags with one or two posts, or merge them into a broader tag.
5. Add descriptions to what remains.

Change slugs of surviving archives only if you must, and redirect when you do. Archive pages accumulate links and traffic like any other URL — the same care as in deleting, merging or redirecting.

Categories, tags and clusters

Clusters — a pillar page with linked supporting articles — are a third way of organising content, and they complement rather than replace the other two.

Categories organise the whole site into sections. Tags provide cross-cutting indexes. Clusters create deliberate reading paths through a subject using links within the articles. clusters and pillar pages covers building them.

A category archive can serve as a rough pillar for a small blog, but a written pillar page is almost always more useful, because it explains and recommends rather than listing.

Deciding at volume

When articles are published frequently, tag sprawl happens quickly unless tags come from a fixed list.

Keep a list of approved tags with their descriptions, and choose from it for each article. A new tag should be created only when a subject is going to hold several articles, and it should get its description when it is created, not months later.

That one discipline — a controlled list rather than free typing — prevents almost every problem described above, and it belongs in the setup described in setting up a new blog.

Related reading

If this was useful, these cover the questions that usually come next.

• Setting up a new blog — where categories get decided
• Clusters and pillar pages — a structure that complements both
• Deleting, merging or redirecting — cleaning up an overgrown archive

The bottom line

Categories are five to eight broad sections; tags are a controlled index of specific topics, two to four per post. Index archives that have several posts and a written description; noindex thin tags and date archives. Clean up duplicates by merging and redirecting, and prevent sprawl by choosing tags from a fixed list.

FAQ

What is the difference between categories and tags?

Categories are the broad sections of a blog, and every post belongs to one. Tags are specific topics that cut across sections, used as an index. A post normally has one category and two to four tags.

How many categories should a blog have?

Five to eight for most blogs. If posts routinely need three or more categories, the categories are too narrow.

Should tag pages be indexed?

Tags with several posts and a written description can be. Tags with one or two posts should be noindexed or merged, since they duplicate the posts they list.

Do too many tags hurt SEO?

They produce many thin archive pages that duplicate each other and the posts themselves. That wastes crawling and creates pages likely to be judged low value. Merging duplicates is worth doing.

Can I rename or merge tags without losing traffic?

Yes, if you redirect the old archive URL to the new one. Archive pages collect links and traffic like any other URL, so treat changes to their slugs with the same care.

Should a tag ever match a category name?

No. That creates two archive pages listing largely the same posts. Keep the category and choose more specific tags.