Sitewide link
A sitewide link is a link repeated across all the pages of a site, usually because it sits in the menu, sidebar or footer.
A sitewide link is a link repeated on all the pages of a site, usually because it sits in the menu, the sidebar or the footer. Your own site is full of them: the link to your homepage, your contact page, your privacy policy. When people talk about sitewide links in SEO, though, they usually mean one site linking to another from every page.
They matter because they look like a lot of links and count for very little. A blog with 2,000 pages and your link in its footer gives you 2,000 backlinks in an SEO tool, from one site that mentioned you once.
Good and bad sitewide links
Plenty of sitewide links are normal. A web agency credits itself in its clients' footers. A shop links to its parent company. A blog lists its partners in the sidebar. Nothing wrong there.
The trouble starts when sitewide links are bought, swapped or stuffed with keywords. A footer link that says "best cheap coffee beans UK" on an unrelated site is the sort of thing Google's spam policies call a link scheme, and Google can ignore it or act against the site behind it. If a link is paid for, mark it with rel="sponsored".
For example, if Kestrel Roasters sponsors a local running club, a "Sponsored by Kestrel Roasters" note in the club's footer is fine, marked as sponsored. A hidden footer link with keyword text on fifty unrelated blogs isn't.
For AI search
AI platforms care less about how many links point to you and more about what pages say. One sentence on a respected page that explains why your coffee is worth buying does more for an AI answer than a footer link on a thousand pages.