One rule for every tag: lowercase, no duplicates, and every post where it belongs.
What it does
It adds a page under Herramientas (Tools) listing every tag that contains a capital letter and showing what will happen to each one: the original name, the lowercase result, the action and how many posts it has. This preview changes nothing.
Once you confirm, it processes them all at once. If the lowercase version doesn't exist, it renames the tag. If it does, it merges them: it adds the lowercase tag to all the posts and deletes the duplicate.
Why standardise
Tags capitalised differently depending on who created them make for an uneven list in the admin and on the site, and when the same tag exists in two versions, posts on one topic end up split across two archives. Converting everything to lowercase gives you a single rule, and merging brings the scattered posts back together.

kokoa-lowercase-tags-1.png
kokoa-lowercase-tags-2.pngHow it works
- Open Herramientas → Lowercase Tags (Tools → Lowercase Tags) and review the table: green rows will be renamed (renombrar), red rows merged (fusionar).
- If everything looks right, click Convertir todo a minúsculas (Convert all to lowercase).
- Check the results table to see which tags were renamed or merged and how many posts each had.
Requirements
- A WordPress administrator account.
Want it on your WordPress site?
We'll install it, tailor it to your site and run the conversion with you.