Settings → Checking your own redirects, and a Check them now button on the Redirects screen.

A redirect rots quietly. You point /old-prices at /pricing, and a year later somebody renames /pricing. Now everybody following a link from an old newsletter is caught by your redirect and sent to a dead end anyway — and nothing tells you, because the rule is sitting in the list looking perfectly healthy.

So once a week the plugin asks whether each destination still answers. Anything wrong is marked in the list, counted on the Dashboard, and the redirect list can be filtered down to just those. Three things it looks for:

The destination is not found — it asks the site for the address and gets a 404 back. A redirect whose next step is a redirect you marked 410 (gone) is reported this way too.
It points at another redirect — which works, but costs the visitor a second round trip and search engines discount the second hop. See below: one press points it at the final address.
It points at itself — which would send a browser round in circles. Caught when you write one too, but a site can move under a rule that was fine yesterday.
It sends visitors round in a circle — two or more redirects that lead back to one already passed, such as /a to /b and /b to /a. Every visit ends in the browser's "too many redirects". Nothing is offered here, because a circle has no final address: decide which one should answer and change or delete the other.

Two things are deliberately not judged, because a warning that is usually wrong is one nobody reads:

A destination on somebody else's site. A slow or blocked third-party host would have your dashboard reporting their site as your broken redirect.
A section rule. /blog/ to /news/ answers a different address for every visit, and plenty of sites serve /news/hello while /news itself is a 404 — because the prefix belongs to a permalink structure rather than a page.

The weekly check works through sixty destinations at a time, oldest first, so a site with four hundred redirects gets round them over a few weeks rather than asking itself four hundred questions at once. Check them now does the same sixty immediately and says how many are left.

Pointing a redirect straight at its final address#

A chain is easy to make without noticing. You point /old-prices at /pricing, and later rename /pricing to /plans: the plugin keeps /pricing working with a redirect of its own, and yours now goes through it. The plugin moves the redirects it made for a renamed page along with the page, but it never rewrites one you wrote, so yours is left pointing at the old address until you say otherwise.

So a redirect marked points at another redirect has a button under its destination naming where it would go: Point it at /plans. Press it and the redirect is changed to send its visitors straight there, as if you had edited it, and nothing else about it changes. It follows the redirects after it the way a visitor's browser does, up to five, and stops early where going further would change what you meant:

Before a temporary redirect. If the next step is a 302 or 307, something is away for now and meant to come back, and a permanent redirect pointed past it would go on skipping it after it does. The row says The next redirect is temporary, so this one keeps pointing at it. and has no button. A temporary redirect further along is pointed up to, not past.
At an address on another site, which is the end of the road.
At a section rule. Its destination for this one address is worked out as a visit's would be, so /blog/ to /news/ gives /news/hello for a redirect pointing at /blog/hello.

The button names the address as it is when the list is drawn. If the redirects after it change in another tab before you press it, nothing is changed and the screen says so, rather than pointing it somewhere you did not see.

To do several at once, tick them and choose Point each straight at its final address under With the ones ticked…. Nothing changes when you press Apply: the screen asks first, naming how many it would change and listing them, and says how many of those you ticked stay as they are. Only your answer changes them, and only while the ticked redirects are the same as when you were asked; if one has been edited in another tab in the meantime, nothing is changed and you are told to look again. Opening the address of that action in a new tab asks again and changes nothing.

Saving a redirect in the form whose destination is itself redirected keeps exactly what you typed, and the sentence after the save offers the final address with the same button: That address is redirected to /plans. Point this one at /plans instead? Ignore it and nothing changes.

A redirect pointed straight leaves the count at once, on the Dashboard, above the list and in the list's Pointing at another redirect filter, which shows how many there are. The next weekly check looks at its new destination afresh. Redirects pointing at another redirect are counted apart from dead ends, because their visitors still arrive. A redirect the plugin made for a renamed page becomes yours once it is pointed elsewhere, as it does when you edit it.