This article describes how FiboFilters decides which filtered pages get indexed by search engines. This determines if a given page will be visible on the search engine results page.
If you’re new to SEO Rules, read the guide to SEO Rules in FiboFilters first.
How search engines work
Before search engines – like Google – can index a page and show it in search results, they first need to discover it. One common discovery method is reading the website’s sitemap.
Sitemap
A sitemap is a list of pages that you want search engines to crawl. It acts as a roadmap, helping crawlers find pages they might otherwise miss.
Robots meta tag
Once a search engine crawler (also known as a bot) lands on a page, it looks for signals indicating whether the page should be indexed.
One such signal is the robots meta tag:
- If this tag is set to
noindex, the crawler will leave without indexing the page. - If no robots meta tag is present, the bot assumes the page can be indexed.
Canonical link
Another signal is the canonical link, which tells the bot whether a given page is a duplicate of another page or is itself the canonical (primary) version.
The rel="canonical" tag is used to point bots to the proper page for indexing:
- If
rel="canonical"points to a different page, the current page is not indexed – the linked page is indexed instead. - This tag is not mandatory. Without it, bots will analyze the page themselves and decide whether it’s canonical.
Why this matters
If you skip the sitemap, robots meta tag, and canonical link, you leave it up to the bots to decide what gets indexed – and their choice may not match what you consider most important.
For more details on how Google discovers and indexes content, see the Google SEO Starter Guide.
FiboFilters behavior
FiboFilters automatically manages the sitemap, robots meta tag, and canonical link based on your shop’s current state – no manual configuration required.
Shop page states
From FiboFilters’ perspective, a shop page can be in one of three states:
- No filters applied
- Filters applied + a matching SEO rule is active
- Filters applied + no matching rule, or a matching rule that is inactive
FiboFilters analyzes the page state to determine what the canonical link should be, whether the page should be indexed by crawlers (by injecting the robots meta tag), and whether it should be included in the sitemap. Here’s a quick cheat-sheet:
| example URL | matching rule | canonical | robots | sitemap |
example.com/product_category/shoes | – | up to SEO plugin | up to SEO plugin | up to SEO plugin |
example.com/product_category/shoes?color=black | no rule | - (no canonical link) | noindex, follow | not included |
example.com/product_category/shoes?color=green | inactive | - (no canonical link) | noindex, follow | not included |
example.com/product_category/shoes?color=red | active | example.com/product_category/shoes?color=red(self-canonical) | – (equivalent to index, follow) | included |
No filters applied
If no filters are applied to a page, FiboFilters makes no changes to it. Your SEO plugin is responsible for determining the canonical link, indexability, and sitemap inclusion.
Filters applied + a matching active rule
If filters are applied and FiboFilters finds a matching, active SEO rule, it makes the page self-canonical by injecting the following tag into the page HTML:
<link rel="canonical" href="https://example.com/product_category/shoes?color=red" />
The page will be indexable by crawlers. FiboFilters does not declare content="index, follow" explicitly, since search engine crawlers index page content and follow all links by default.
This URL is included in the sitemap.
Filters applied + no matching or active rule
If filters are applied but FiboFilters finds no matching rule – or the matching rule is inactive – it marks the page as non-indexable:
<meta name="robots" content="noindex, follow" />
The directive is set to follow (not nofollow) so that crawlers continue to follow all links on the page, even though the page itself will not be indexed.
This URL is not included in the sitemap.
FiboFilters and SEO plugins
If you’re using an SEO plugin, it will use the FiboFilters’s canonical link on filtered pages that match an SEO rule. If there’s no SEO rule defined for selected filters, FiboFilters will set the noindex tag via the SEO plugin’s hook and ask it to remove the canonical link. If you would still like to include the canonical link for noindex pages, you can use the fibofilters/seo/canonical_on_noindex hook for that.
Read more about supported SEO plugins here.