Link Checker docs
Link Checker documentation
This is the reference for how checks work. Guides for the WordPress plugin and the cloud monitor follow with the first release.
Statuses
- OK
- The link answers. Nothing to do.
- Redirect
- It works, through a detour. Point it at the final address and save a hop.
- Broken
- 404, 410, a host that does not exist, or a server that still fails after a retry. Replace it, link an archived copy, or unlink it.
- Blocked by bot protection
- The site refused an automated visitor (403, 429 or a challenge page). People can usually open it, so it is never counted as broken.
- Skipped
- An address that cannot be checked from outside, such as a private network address.
How a link is judged
| Answer | What we report |
|---|---|
| 200 to 299 | OK |
| 301, 302, 303, 307, 308 | Redirect, with the final address (up to 5 hops) |
| 404 or 410 | Broken |
| 5xx or a timeout | Retried once after a pause; broken only if it fails again |
| 403, 429, a captcha or challenge page | Blocked by bot protection, never broken |
| 405 or 501 to a HEAD request | Asked again with GET before anything is decided |
| Host not found | Broken, with the reason |
User agent and allow-listing
Checks identify themselves as AmboltLinkChecker/1.0 (+https://ambolt.dev/link-checker). They send a HEAD request first and fall back to GET when a server refuses HEAD, follow up to five redirects, and check at most two links per host at the same time.
If your firewall or bot protection challenges the checker, your own links show as blocked, not broken. To check them, allow that user agent in your firewall rules. The checker never fills in forms and never follows links on the pages it checks.
The free online check
The online check reads one page and checks up to 60 of its links within a short time budget. It is meant for people: one check per visitor a day, counted only when the check finishes. For automation, the Agency plans include an API and webhooks.
WordPress plugin
Coming soon to WordPress.org. Its guide (installation, the background queue, bulk fixes and the e-mail digest) is published here with the release.
Cloud monitor and API
Billing and the cloud monitor open with the first release. See the plans. Questions: hello@ambolt.dev.