Link Rot Checker — spaceless.com

Link rot is what happens to the web over time. Pages move, servers die, organisations dissolve, funding ends. Tim Berners-Lee identified the problem in 1998 and argued for persistent URLs; the web has largely ignored the advice ever since. A Harvard study found that half of all URLs cited in Supreme Court opinions no longer worked. The picture in academic papers, blog posts, and personal reading lists is not much better.

Paste up to 25 URLs below — one per line. Each is checked in turn using a HEAD request, so the check is fast and puts minimal load on the target server. Dead links get an automatic Wayback Machine lookup link; redirected links show where they now point.

The web forgets. This helps you remember.

Check URLs

One URL per line — up to 25

http:// and https:// URLs only — no login or account required.

What the codes mean

200 Live OK — the page exists and is accessible. All is well.

301 Redirected Moved permanently — the URL has a new home. Update your reference to the new address shown.

302 Redirected Temporary redirect — officially, the original address is still considered valid. In practice, update it anyway.

403 Dead Forbidden — the server knows the page exists but won’t serve it. Sometimes this is a login wall; try the Wayback Machine for a cached copy.

404 Dead Not found — the commonest form of link rot. The page is gone from this address. Check the Wayback Machine; try a search engine with the page title.

410 Dead Gone — rarer than 404, and more honest: the server is explicitly confirming the page has been removed and will not return.

429 Blocked Too many requests — the server rate-limited the check. The page almost certainly exists; try visiting it directly in your browser.

500 Error Internal server error — the host is reachable but something has broken on its end. Often temporary; try again later.

503 Error Service unavailable — the server is overloaded or down for maintenance. Usually temporary.

0 Unreachable No response at all — timeout, DNS failure, or the host no longer exists at this address. The most severe form of rot: the server itself is gone.

Some servers reject HEAD requests with a 405 (Method Not Allowed) response; the checker retries these automatically using a GET request. Results marked “via redirect” resolved successfully after following one or more redirects; the original URL has moved.

The Wayback Machine at the Internet Archive has been archiving the web since 1996. For any live link, you can Save a Page Now — free and account-free. Archiving takes seconds; the window before a page disappears can be much shorter. Save while you can, not after the fact.

Tim Berners-Lee wrote about link rot in his 1998 note Cool URIs don’t change. Twenty-seven years on, the title still says everything there is to say on the matter.