Free Online Tool

IP Blacklist Check

Enter a public IPv4 address to check whether it appears on common DNS-based blacklist providers used for spam and abuse signals.

Check IP reputation blacklist signals

DNS-based blacklists, also called DNSBLs, are used by some email and abuse filtering systems. If an IP address appears on a blacklist, email delivery or server reputation may be affected.

Listed: the DNSBL provider returned a blacklist record.
Not listed: no blacklist record was returned by that provider.
Signals only: blacklist results are not a final reputation score.
IPv4 focused: most DNSBL checks are designed for IPv4 addresses.

How to use

Enter a public IPv4 address such as 8.8.8.8.
Click Check Blacklists.
Review which DNSBL providers returned a listing signal.
Use IP Lookup and Reverse DNS for additional context.

FAQ

What is an IP blacklist?

An IP blacklist is a reputation list that may include IP addresses associated with spam, abuse, malware, open proxies, or other unwanted traffic.

Does one listing mean my IP is bad?

Not always. DNSBL listings are signals. Different providers have different policies, and some listings may be temporary or unrelated to your current usage.

Can this check email deliverability?

It can help identify blacklist signals that may affect email delivery, but complete deliverability also depends on SPF, DKIM, DMARC, rDNS, mail server behavior, and domain reputation.

Why are private IPs blocked?

Private and reserved IP addresses are blocked because public DNSBL checks apply to public internet IP addresses.