What broken links cost

How it works

Internal links connect the pages of your website. Crawlers follow them to find new pages and infer from the linking which pages matter. Visitors use them to move on.

A link is broken when its target does not answer or returns an error status of 400 or above, usually 404. That happens when pages are renamed, moved or deleted and the links to them stay. A single broken link hardly hurts your ranking. Many of them, though, suggest the site is not looked after, and visitors leave.

bytereport checks a sample of up to 20 internal links on the start page. Each link is followed to the end of its redirects. If there is no answer or it ends with status 400 or higher, it counts as broken. If the start page has no internal links at all, crawlers find no further page from there; that happens when the navigation is only built by JavaScript.

What matters

• Fix the target. Where the page still exists, put the correct address in the link.
• Redirect old addresses. Where an address has changed, redirect the old one to the new one with status 301. That way links from other websites and bookmarks keep working too.
• Keep redirects to a minimum. A link that only reaches its target through a redirect works, but costs an extra request. bytereport lists such links but does not count them as errors. Better to link to the final address directly.
• Links in the HTML. Crawlers follow links in <a href="…">. Navigation made only of scripts with click handlers is invisible to them.

How to set it up

You fix broken links in the CMS, wherever the link sits: in the menu, the text or the template. Many CMSs have plugins that create a redirect automatically when you rename a page. At server level, a 301 redirect in nginx looks like this:

location = /old-page {
    return 301 /new-page;
}

bytereport's sample covers the start page only. For the whole site, Google Search Console shows under Indexing · Pages which addresses answer with 404.