DNS Checker Bot IP Addresses

WebCheck Crawler IPs

Echo DNS Scanner IPs (dedicated)

These servers are always online and may send DNS queries at any time. Each address has matching forward and reverse DNS (PTR) records for verification.

Echo DNS Scanner IPs (on-demand)

Scan capacity is created for a measurement window and removed once the run finishes, so these addresses are only active during a scan. The addresses themselves are reserved permanently by DNS Checker and are never reassigned to anyone else, so they are safe to allowlist even while idle. Forward and reverse DNS are set on every one.

List last updated 2026-08-10. Machine-readable formats: ips.json and ips.txt.

Allowlisting in bulk

Matching on reverse DNS is more durable than pinning individual addresses: on-demand scan capacity is created and destroyed per run, so a pattern rule keeps working where a copied list goes stale.

• *.dnschkr.com, web crawlers and the DNS measurement fleet.
• *.scanner.dnschkr.com, DNS measurement fleet only.

Scope: These patterns cover DNS Checker's web crawler and DNS measurement fleet, which are the systems documented here.

Verification

To verify a request is from DNS Checker:

1. Perform a reverse DNS (PTR) lookup on the source IP. It should resolve to a *.dnschkr.com hostname.
2. Perform a forward DNS (A) lookup on the hostname. It should resolve back to the original IP.
3. For web requests, confirm the User-Agent contains DNSChkr-WebCheck.

Machine-Readable Format

This list is also available as JSON and plain text.