I present to you, a gift, a gift of a service that will "unrot" your links, cleverly named… unrot.link.
The service promises to prevent and undo link rot on long lived web sites, via a service based implementation of my No More 404 method, free for all.
I've published as much documentation that I could think would be useful on the unrot.link web site, including an interactive walkthrough of how the server side process works (for the nerds and those who want to port to their own language).
When I originally wrote the post on No More 404, one concern was the 2 second timeout - both for myself but also raised by Chris Coyier. This new version tries its best to do away with using multiple methods (a DNS resolution check and HEAD requests to attempt to reducing the latency). This mostly does work, and on the test page I rarely see 2 seconds, and in some cases where there's a redirect, it can happen in under a second.
Also, importantly, the client script (that does the progressive enhancement) has built in redundancy to protect against the unrot service going down: a "ping" is used and only if it succeeds does the script progressively enhance.
Finally, the service has an allow list. This means I have some way of contacting users of the service if there's any need. The process is relatively straightforward via a request on GitHub (as documented). If the access isn't in place, the unrot service will ignore the redirect check and forward you to the original requested URL (effectively a no-op).
Other than that, do check it out, and give me any feedback/PRs if you see room for improvement: https://unrot.link
