How are "related posts" chosen in WordPress, and why do unrelated posts show up?
In short: Most themes that don't use a plugin build the "related posts" list from the post's categories, so the list is only as tidy as your categories. If you see unrelated posts, the usual reason is a post sitting in two categories, one of them "Uncategorized". Wiozen Theme shows the 3 newest posts from the same categories under each article; it leaves out the post itself, doesn't push sticky posts forward and ignores tags.
How do related posts lists usually work?
There are three common methods. The first is category: other posts in the same category are shown. The second is a weighted mix of tags and categories. The third is plugins that compare the text of your posts; these can be more accurate but do extra database work on page load or in the background.
The category method is fast and you can predict why a post appears. Its weak spot is that a messy category setup gives you a messy list.
How does Wiozen Theme pick related posts?
The theme doesn't use a plugin for this. The list on a post page looks at all the categories of the post being read and pulls posts that are in any of them. The current post is left out and sticky posts aren't moved to the top. Tags aren't used.
- In the News and Finance designs the heading is "Related news", in Technology "Read next", in Food "You may also like". All four show the 3 newest posts by publish date.
- In the Guide design the heading is "More guides on this topic". It shows 6 posts sorted by last update, so a guide you just revised moves up the list.
- In the Guide design, glossary terms are kept out of related guides. If the post being read is itself in the glossary category, that filter isn't applied.
Posts written with the Content Bot carry the bot's own "Related articles" list inside the text. The Guide design removes that list and shows only its own section, so the page doesn't end up with two lists. The other four designs leave the post text untouched.
Why do unrelated posts show up?
Because the list matches on any of a post's categories, one extra broad category changes the whole result. These are the most common cases:
- The post is in its own topic and also in "Uncategorized". WordPress puts every post without a chosen category there; over time it becomes the biggest category and fills the list.
- Categories that describe placement rather than topic, such as "Top stories", "Featured" or "Headlines". They collect posts on every subject.
- There are no other posts in the category. The list is then empty, which is normal for a category you just created.
How do you fix the list?
- Check the post counts on the Posts › Categories screen. If more than half of all posts sit in one category, that category is useless for related posts.
- Put each post in one topic category. Remove "Uncategorized" from posts, or set a real topic as the default category under Settings › Writing.
- If you need to mark placement (headline, featured), make the post sticky or use a tag instead of a category. Neither affects the related posts list.
- Keep at least 4 posts in each category. With the current post left out, that fills all 3 cards.
Changing how many posts are shown
The list is a Query Loop block in the single post template in the Site Editor. Open the template, select the block and change the items per page in the settings sidebar. As long as the block keeps its "wiozen-related" CSS class, the theme keeps applying the category filter.
If you add a new Query Loop block to the template yourself, it doesn't behave like related posts and picks from every post on the site. For the same behaviour, type wiozen-related in the block's Advanced › Additional CSS class(es) field. If you only want to leave out the post being read, the wiozen-exclude-current class is enough.
A template you changed in the Site Editor stays the way you left it even when you switch designs. To go back to the new design's own template, reset it under Customize › Customized templates in the theme panel.
Frequently asked questions
Should I install a separate related posts plugin?
Not with Wiozen Theme; the list comes with the theme. If you add a plugin, the post page ends up with two lists and you'll need to remove one.
Does the list use tags too?
No, only categories. Your tags appear as their own row on the post page.
Can related posts be sorted by most read?
The theme has no view counter. Sorting is by publish date, or by last update in the Guide design.
Can I keep one post out of related posts entirely?
There's no direct setting. Moving the post to a different category takes it out of the lists for posts in the old one.
If you're setting up categories from scratch, see the news or tech site setup guide; to try the theme, download Wiozen Theme for free.