Validators

IP Blacklist Checker

Check if an IP address is on spam or abuse blacklists. See your IP reputation across 10+ databases.

Checking IP reputation...

Scanning 10+ blacklist databases

What is an IP Blacklist?

An IP blacklist (also called a DNSBL - DNS-based Blackhole List) is a real-time database of IP addresses flagged for spam, malware, or abuse. When you send an email, visit a website, or connect through a proxy, the receiving server checks your IP against these lists before deciding whether to let you through.

Step 1

Your IP connects to a server or sends an email

Step 2

Server queries DNSBL lists and abuse databases in milliseconds

Step 3

Listed? Traffic gets blocked, throttled, or flagged for review

Why Does IP Reputation Matter?

Your IP is the first thing servers evaluate - before cookies, headers, or content. A blacklisted IP silently breaks things even when you've done nothing wrong.

Email deliverability tanks - a single DNSBL listing can route all your messages to spam across Gmail, Outlook, and Yahoo.
Proxy and automation traffic gets blocked - datacenter IPs are frequently blacklisted from prior misuse, causing silent failures in scraping and account management.
Platform accounts get flagged on login - Instagram, TikTok, and Google cross-check IP reputation as a risk signal during authentication.
CDN-level blocks kick in - Cloudflare and Akamai use threat feeds that overlap with public blacklists, triggering 403 errors or CAPTCHA loops.

What We Check

10+

blacklist databases
checked in parallel

We query widely used DNSBL lists in email and web infrastructure, including Barracuda, SpamCop, UCEPROTECT and PSBL, simultaneously via DNS lookups. Results come back in seconds.

On top of that, we pull crowdsourced abuse intelligence: confidence scores based on reports from sysadmins worldwide, ISP classification, usage type detection, and Tor exit node flagging.

How to Fix a Blacklisted IP

If your IP shows up on one or more lists, here's what to do - fastest options first.

Rotate to a clean IP

The fastest fix. Switch proxies or request a new IP from your provider. Mobile carrier IPs are almost never blacklisted - they're shared among millions of legitimate users.

Request delisting

Most DNSBL operators have a self-service removal form. Once the abuse source is resolved, submit a delisting request. Processing typically takes 24–72 hours.

Contact your hosting or proxy provider

On a shared service? Your provider owns the IP block's reputation. They should handle delisting or swap you to a clean range.

Wait for auto-expiry

Some lists (like SpamCop) automatically clear after 24–48 hours of no new reports. If the abuse has stopped, the listing may resolve on its own.