Fixing Tags, Categories, and RSS in Our Eleventy Blog

Over a short QA pass, I found three regressions:

• Tags pages were 404ing
• Categories index existed but showed no categories
• The RSS feed at /feed.xml was 404ing

Here’s how we addressed each one.

Tags 404

• Problem: The template at src/tags.njk expected a collections.tagList for pagination, but no such collection was defined.
• Fixes:
  • Added a tagList collection in .eleventy.js that reads tags from src/blog/**/*.md and de-duplicates by slug to avoid permalink collisions.
  • Added a tags index page src/tags/index.njk that lists all tags with counts.

Key code: .eleventy.js addCollection("tagList", ...) returns a unique, sorted list of tag names.

Categories empty

• Problem: The index page at src/categories/index.njk expected collections.categoryList, which didn’t exist.
• Fixes:
  • Added a categoryList collection in .eleventy.js by pulling the category frontmatter from posts.
  • Per-category archive pages are generated by src/categories.njk with pagination over the category list.
  • Resolved an output conflict by disabling a redundant src/category.njk (now permalink: false).

RSS 404

• Problem: src/feed.xml referenced collections.posts and used an htmlToAbsoluteUrls filter that wasn’t defined yet. When collections or filter initialization failed, the feed failed to build.
• Fixes:
  • Confirmed a posts collection sourcing from src/blog/**/*.md (sorted by date desc) in .eleventy.js.
  • Implemented a lightweight htmlToAbsoluteUrls filter to convert relative links in post content to absolute URLs using site.url.

Result

• /tags/ works and lists tags; individual tag pages paginate correctly
• /categories/ shows categories with counts and links to per-category pages
• /feed.xml builds and includes the latest posts

If you want to extend this further, consider:

• Adding tag or category descriptions
• Hiding utility tags (already ignoring all, nav, post, posts)
• Using a custom slug function if you need locale-specific slugs

Happy shipping!