IP Reputation Checker
Look up any domain's IP address and reverse DNS. For blocklist status of the same IP, pair this with our Blacklist Checker, which queries the DNSBLs live.
About this check
What is IP reputation?
IP reputation is a score assigned to an IP address based on its historical behavior. Security services track whether an IP has been involved in spam, phishing, malware distribution, or other abuse. A poor IP reputation can cause email deliverability problems, trigger CAPTCHAs for your visitors, or get your server blocked by firewalls.
Why does IP reputation matter?
If your domain resolves to an IP with a bad reputation, your emails may land in spam folders and your website visitors may see security warnings. Shared hosting makes this worse: another tenant on the same IP can damage your reputation. Regularly checking your IP reputation helps you catch issues before they affect your users.
What is reverse DNS?
Reverse DNS (rDNS) maps an IP address back to a hostname. Mail servers use rDNS as a basic trust signal. If your IP has no reverse DNS record, or the record does not match your sending domain, some mail servers will reject your messages outright. A properly configured rDNS record is a baseline requirement for email deliverability.
How do I fix a bad IP reputation?
Start by identifying the root cause: compromised accounts, misconfigured mail servers, or a shared hosting neighbor. If you are on shared hosting, contact your provider or move to a dedicated IP. For abuse reports, address the underlying issue and request delisting from the reporting databases. Prevention is key: monitor your IP reputation regularly and set up alerts for changes.
FAQ
Operator questions, answered.
Is this IP lookup free?+
Yes, completely free. No signup or credit card required. Enter any domain to instantly resolve its IP address and reverse DNS.
What data sources do you use?+
We resolve the domain's IP address via a live DNS query and perform a reverse DNS lookup. Abuse-database lookups (such as AbuseIPDB) are currently disabled on this scanner, so no abuse score is shown: when we cannot check something, we say so rather than display a made-up value.
How do I check whether this IP is on blocklists?+
Use our Blacklist Checker tool. It queries Spamhaus ZEN, SpamCop, Barracuda and SORBS live over DNS for the resolved IP, plus the Spamhaus DBL for the domain itself.
My IP has a bad reputation elsewhere. What should I do?+
First, check whether you are on shared hosting, as another tenant may be responsible. If you control the server, audit for compromised accounts, open relays, or misconfigured services. Once the issue is resolved, submit a delisting request to the reporting database and monitor for recurrence.
IP Reputation Checker is one slice of the full scan.
A free CQwerty scan covers TLS, DMARC / SPF / DKIM, DNS, headers, WHOIS, exposed files and spam blocklists in a single 90 second submission.