Hard rot versus soft rot, the split most link checkers miss
Link rot splits into two categories that behave completely differently, and almost nothing written about it makes the distinction clearly. Hard rot is what most people picture: a URL that now returns a 404, or a domain that no longer resolves at all. It is loud, it is obvious, and any basic link checker catches it instantly by just reading the HTTP status code.
Soft rot is quieter and far more common than the tools people use to find it would suggest. The URL still returns a normal 200 response. The page still loads. But the content behind it has changed enough that the link no longer does what it was supposed to do: a domain lapsed and got bought by a squatter or an ad-parking service, an article got rewritten around a different topic, a product page now points at something else entirely. A checker that only reads status codes reports every one of these as fine, because from a pure HTTP standpoint, nothing broke. This is exactly why an automated audit that only checks for 404s will always understate how much of a site's dead links actually are dead. It is not measuring the thing that actually matters to the person clicking.
| Type | What happened | What a status-code checker sees | How to catch it |
|---|---|---|---|
| Hard rot, deleted page | The page was taken down | 404, correctly flagged | Any standard link checker |
| Hard rot, domain expired | The domain was not renewed | DNS failure or timeout, correctly flagged | Any standard link checker |
| Broken redirect | A redirect target was deleted or misconfigured | 404, a loop, or an error, correctly flagged | Any standard link checker, or a manual redirect test |
| Soft rot | Content was replaced, repurposed, or the domain was resold | A normal 200, missed entirely | Reading the actual page, not just the status code |
| Mass rot | A third-party shortener you relied on shuts down | Every link it ever issued fails at once, at any time, regardless of age | Not relying on a shortener domain you do not control |
Why links rot in the first place
Most rot has a boring cause. A site gets redesigned and the new URL structure does not carry a redirect from the old one. Old content gets pruned during a cleanup and nobody checks what was still being linked to. A domain's renewal lapses, often by accident, and the registration is picked up by someone else within days. None of these require anything unusual to happen. They are just what happens to the web by default when nobody is specifically maintaining a link's destination.
There is a fifth cause worth calling out on its own, because it behaves differently from the rest: relying on a url shortener you do not control. If that company shuts down, gets acquired and sunsets the product, or simply stops renewing its own domain, every link it ever issued for every customer can go dark at the same moment, no matter how recently any one of them was created. That is not gradual decay, it is a single point of failure sitting underneath links you thought were independent of each other. Putting a shortener on your own domain does not remove the platform dependency underneath it, but it does mean the address people actually see and share stays yours even if you later move to a different provider.
Why link rot costs more on paper than it looks like it should
A broken link in an old blog post is annoying but recoverable, you can edit the anchor and fix it in seconds. A dead link on printed material is a different problem entirely. A QR code on a business card, a poster, or packaging cannot be edited after it is printed, so if the destination rots, every physical copy still in circulation is now pointing at nothing, permanently, until someone reprints the material. This is a real reason to treat the redirect layer behind a printed QR code as infrastructure worth maintaining carefully rather than a one-time setup step. See QR code best practices for print for what that looks like.
On the web specifically, rotted links quietly erode the value of anything that pointed at them: a citation whose source disappeared, a backlink that no longer leads anywhere real, a reference in an old article that now sends a reader to an unrelated site. None of it announces itself: it just sits there until someone happens to click.
How to detect link rot before your audience does
A periodic manual pass through your own older content, checking anything more than a year or two old, catches most hard rot quickly. For soft rot, status-code checking alone will not do it. You need something closer to a content diff, or at minimum a spot check where a human actually reads what the link currently leads to, not just whether it responds.
Click data is a useful early signal too, if you have it. A tracked link that keeps receiving clicks but shows an unusually short time on the destination page, or a sudden change in behavior after months of being steady, is worth a manual look even if the status code reads as a perfectly healthy 200.
How to prevent link rot on your own links
When a URL genuinely has to move, leave a permanent redirect behind rather than just deleting the old path. That is the entire mechanism covered in what is a redirect, and it is the single most effective thing most sites fail to do. The other real advantage of routing links through a tool you control, whether that is a url shortener or a link-in-bio page, is that the address stays fixed even when the destination changes. If a product page moves, you update the one redirect target behind the short link once, instead of needing every place that link was ever shared, a bio, an old post, a printed flyer, to be individually updated. That is the actual value of an indirection layer, separate from any click tracking it happens to also provide.
What to do when you find a rotted link
For your own content, fix the destination directly, or point it at an archived version if nothing current covers the same material. For a link to someone else's page that you referenced, look for an updated source first rather than defaulting to an archive snapshot, since a snapshot will not reflect anything the original author changed after it was taken.
One honest limit worth stating plainly. A click tracking tool, Raydar included, can only see activity on the links and pages it actually serves. It has no visibility into whether some other site's URL you reference has rotted, and it cannot warn you the moment a third-party shortener you rely on for other links shuts down somewhere else on the web. Detecting rot outside your own tracked links is still, for now, a manual habit rather than something a dashboard does for you.