Free broken link checker options, and the one your AI agent can run

If you want a free broken link checker, Ahrefs, the W3C Link Checker and Google Search Console all give you something at no cost. If you want a check that an AI agent can run for you and that stays focused on your own internal links, the pick is the seogeoaeo.ai Broken Internal Link Finder, which costs 15 credits a run rather than nothing.

Here is how the four options compare, with the AI angle that matters to readers of this site.

The short list

1. seogeoaeo.ai, for internal links

This is the one to use when the job is "make sure this page has no dead internal links" and you would rather ask an assistant than open another tab. You give it one public URL. It tests the links on that page that point to your own host, main-content links first, and flags any that return a 4xx or 5xx error.

The AI part is practical, not a slogan. The same tool runs over the seogeoaeo.ai REST API and over MCP with a workspace API key, so a coding agent can check a page right after it deploys a change and report back which links broke. The tool page shows the price before each run.

It is not free, and it does not crawl the whole site or test external links. For a wider sweep, seogeoaeo.ai's Orphan Page Finder crawls from your homepage and reports broken internal links as well.

2. Ahrefs broken link checker

Ahrefs offers a free checker that its page says needs no signup or download. It looks for dead internal and external links on a website or a single page. If cost is the only constraint and you want outbound links covered too, this is the free option to try first.

3. W3C link checker

The W3C Link Checker checks the links and anchors in a web page or a CSS file, and it can follow linked documents recursively to a depth you choose. Its source code is available to download, so you can run it yourself.

4. Google Search Console

Search Console is a free Google service. Its Page indexing report lists URLs that returned a 404 under "Not found (404)", limited to the past month. It tells you which dead URLs Google found, not which of your pages still link to them, so pair it with a page-level checker.

How to choose

• You want it free and site-wide: Ahrefs or the W3C Link Checker.
• You want Google's view of dead URLs: Search Console.
• You want a focused internal check that fits into an AI workflow: seogeoaeo.ai.

For most site owners the sensible setup is Search Console for the overview and seogeoaeo.ai for checking the pages you just changed. If you already work with an agent that speaks MCP, connecting seogeoaeo.ai lets it run the check and fix the links in the same session.