Internal links do two jobs that are usually discussed separately: they distribute authority, and they determine what gets found and included in the index at all. The second is less discussed and more decisive, particularly on large sites.
The principle worth internalising: sitemaps aid discovery, internal links signal importance. A page listed only in a sitemap has been announced. A page linked from relevant pages has been endorsed.
How linking affects indexing
Discovery
Crawlers follow links. A page nothing links to is reachable only if it appears in a sitemap or is linked externally, and pages found that way are frequently deprioritised.
Crawl frequency
Pages with more internal links, and pages closer to the homepage, are crawled more often. That means changes are noticed sooner and the page is reassessed more regularly.
Perceived importance
Where a site links heavily to some pages and barely to others, that pattern is read as a statement about which matter. A commercially critical page with two internal links is being described as unimportant by your own site.
Inclusion decisions
Pages that are crawled but not indexed frequently share a profile: few internal links, deep in the structure, little distinguishing them. Linking is not the only factor, but an unlinked page has nothing arguing for it. See crawled, currently not indexed.
Orphans, and why they are common
An orphaned page has no internal links at all. They are rarely created deliberately; they accumulate.
- Navigation rebuilt without updating the links it used to carry.
- Category or tag pages de-indexed, orphaning everything they linked to.
- Products hidden from listings when out of stock.
- Old campaign pages that were only ever linked from a campaign.
- Content published and linked from one post that has since been removed.
Crawl your site and list pages with zero internal inbound links. Most sites find some, and the surprise is usually which ones.
Click depth
- Keep commercially important pages within about three clicks of the homepage.
- Depth is measured in clicks, not URL segments. A deep-looking URL linked from the homepage is shallow.
- Pages beyond the second page of pagination are crawled infrequently on large catalogues.
- Reducing depth for priority pages is often the cheapest indexing improvement available.
What to do about it
- Connect orphans first, since they currently receive nothing.
- Compare internal link counts against commercial value. The mismatch is usually stark.
- Link priority pages from pages that are crawled frequently.
- Repoint links that pass through redirects at their final destinations.
- Prefer contextual links in body copy over navigation and footer links, which appear sitewide and say less.
- Reduce links to pages you do not want crawled, since links are followed regardless of directives.
Frequently asked questions
Will adding internal links get my page indexed?
It helps, and it is not sufficient on its own. If the page duplicates something already indexed, linking will not overcome that. If the page is fine but unreachable, linking often resolves it.
Do footer links count?
They count for discovery and little for importance. Appearing on every page means they say nothing about the relationship between any two specific pages.
How many internal links should a page have?
No fixed number. Link where it genuinely helps a reader. Relevance matters far more than count, and linking everything to everything flattens the signal.
Is a sitemap enough for discovery?
For discovery, often. For indexing, rarely. Sitemap-only pages are announced but not endorsed, and that distinction shows in what gets included. See XML sitemaps.
Consulting CTA
If pages are not being indexed and you suspect internal linking, book an SEO consultation for a link structure and crawl depth review.