IP Blacklist & Open-Proxy Reputation Checker (DNSBL)
Updated:
Before assigning a proxy IP to an important ad account, e-commerce store, or email automation workflow, verify that the IP is not listed on public DNS-based Blackhole Lists (DNSBLs). Enter any public IPv4 address above to query 8 major anti-abuse and open-proxy databases in real time.
Which DNSBL Databases Does This Tool Query?
Web application firewalls (Cloudflare, Akamai, AWS WAF) and registration filters cross-reference incoming IPv4 addresses against real-time DNS zones. Our tool checks both spam reputation and open-proxy exposure:
| DNSBL Zone | Focus Area | Impact When Listed |
|---|---|---|
bl.spamcop.net & b.barracudacentral.org | Botnet & Spam Activity | Triggers frequent Cloudflare Turnstile / hCaptcha challenges and blocks transactional emails |
http.dnsbl.sorbs.net & socks.dnsbl.sorbs.net | Known Open HTTP/SOCKS Proxies | Flags the IP as a public shared proxy on e-commerce and social login pages |
dnsbl.sorbs.net & psbl.surriel.com | Aggregate Abuse & Compromised Hosts | Lowers IP trust score across payment gateways and ad networks |
dnsbl-1.uceprotect.net & all.s5h.net | Single-IP Brute-Force & Scraping Abuse | Blocks automated API queries and account signups |
Why Free & Shared Proxies Get Blacklisted Within Hours
- Noisy Neighbor Abuse: When hundreds of strangers share the same public proxy IP, a single user running credential stuffing or spam immediately puts the IP onto SpamCop and SORBS.
- Open Port Scanners: Security crawlers scan the entire IPv4 space daily; any unauthenticated proxy is automatically cataloged in
http.dnsbl.sorbs.net. - Private Allocation Protection: VinaProxy Dedicated IPv4 and Static ISP proxies are protected by
user:passauthentication and allocated exclusively to your account.
Step by step
- 1
Enter the public IPv4 address
Paste your proxy's exit IPv4 address into the input box above.
- 2
Click 'Check IP Blacklist'
Our server reverses the IPv4 octets (
d.c.b.a.zone) and queries all 8 DNSBL zones in parallel. - 3
Review the DNSBL Reputation Report
Verify that the top badge reads 'CLEAN (0 / 8 Blacklists)' and every row displays 'CLEAN'.
- 4
Replace any listed IP immediately
Never log into a high-value seller or ad account from an IP that appears on 1 or more blacklists.
Frequently asked questions
How does a DNSBL lookup work under the hood?
To check IPv4 1.2.3.4 against bl.spamcop.net, the resolver queries the DNS A record of 4.3.2.1.bl.spamcop.net. An NXDOMAIN response means the IP is clean; a 127.0.0.x response indicates the IP is listed.
Why did a free proxy from a public list show LISTED on SORBS?
Public proxies have no authentication, so automated scanners detect them and add them to open-proxy DNSBL zones (http.dnsbl.sorbs.net / socks.dnsbl.sorbs.net). Always use private authenticated proxies for account operations.
Can I combine this Blacklist Check with an ASN check?
Yes! After verifying that an IP is clean on all 8 DNSBLs, run it through our IP & ASN Lookup Tool to confirm whether its ASN is Residential ISP or Datacenter.
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