UASlinkChecker

Listed only

Udger's link checker, which visits the websites of browser, operating-system and robot vendors to confirm they are still reachable while the company maintains its user-agent database. Udger documents the user-agent string it sends but publishes no allowlist of the addresses it crawls from, and states no robots.txt policy for it.

Operated by Udger s.r.o. · Official documentation

User agents

Patterns this directory matches, with real observed strings.

regexUASlinkChecker/\d
observedMozilla/5.0 (compatible; UASlinkChecker/2.1; +https://udger.com/support/UASlinkChecker)

How to verify

No verification recipe published by the operator.

Good Bot Practices scorecard

Identifies honestly
Stable UA token documented (1 pattern)
Verifiable
Operator publishes no verification path
Respects robots.txt
Service traffic you configured — robots.txt does not apply
Behaves
Crawl-rate behavior is operator-declared; not machine-verifiable from this dataset
Reachable operator
Operator and documentation published

Measured against the Good Bot Practices.