Free broken link checker: which 404s actually cost you

Link checkers are among the oldest tools on the web and among the noisiest. The list they produce mixes genuine breakage with a category of false positives that will happily consume an afternoon.

The failures worth acting on

• Internal 404s. The most damaging and the easiest to fix. They waste crawl budget, break the path authority flows along, and land real visitors on an error page.
• External 404s. Less damaging, but they date your page. A resource list where a third of the links are dead reads as abandoned.
• Redirect chains. Each hop costs time and leaks a little authority. Link to the final destination directly.
• http:// links to sites that support https://. An unnecessary redirect on every single click.

The failures that are not failures

A 403 or 429 from a large site is usually bot protection, not a dead page. Social platforms, marketplaces and news sites routinely refuse automated requests while serving browsers normally. Removing those links because a checker flagged them makes your page worse in exchange for nothing.

The rule is simple: verify anything that is not a 404 by opening it in a browser before you touch it.

When link rot happens

Link rot is not gradual. It arrives in batches, and almost always after a migration, a CMS change, or a URL structure redesign — the moments when a large number of internal links become wrong simultaneously.

Which makes the useful habit less about periodic scanning and more about checking immediately after any change that touches URLs. That is when the damage is concentrated and when it is cheapest to undo.

What free means here

Our broken link checker is free, with no account needed for your first scan. It is deliberately polite — capped and time-budgeted, so checking your links never amounts to hammering somebody else's server.