IP, Domain & URL Blacklist Checker
Check an IP address, domain, or URL against 16 active real-time DNSBL and domain blocklist sources with one request. See source-level results in a structured response so you can identify where your infrastructure or web destination is listed without checking each blacklist manually.
What is a blacklist checker used for?
A blacklist checker checks an IP address, domain, or URL against supported blacklist sources and returns structured results showing whether each source reports it as listed or not listed. This free blacklist check helps you investigate email deliverability, security alerts, suspicious infrastructure, and domain reputation from one place.
Instead of checking individual blacklist databases one at a time, ProWebLook brings the results into a single lookup and shows which sources returned a match, a clean result, or an unavailable/error state.
ProWebLook Offers 3 Blacklist Checkers
The blacklist checker supports three practical target types, so you can investigate the infrastructure or destination that is actually causing the problem.
IP Blacklist Checker
Check whether an IP address appears on supported IP-based blacklists. Use this when investigating server reputation, abuse reports, suspicious traffic, or email delivery issues.
Domain Blacklist Checker
Check whether a domain is listed on supported domain feeds and investigate the IP addresses associated with the domain where applicable.
URL Blacklist Checker
Submit a full URL when you need to investigate a web destination. The checker normalizes the URL to its host automatically, so you do not have to extract the domain manually.
Why Does an IP or Domain Get Blacklisted?
An IP address or domain can become listed after behavior associated with spam, abuse, compromised infrastructure, suspicious traffic, or other security activity triggers a blacklist's detection criteria. A listing is a signal to investigate, not automatic proof that the infrastructure is malicious.
Email and spam reputation
If your sending IP or sending domain appears on a spam blacklist, mailbox providers may treat mail from that infrastructure with greater suspicion. A blacklist check can help identify whether a reputation issue is connected to the sending infrastructure.
Security and threat investigation
Blacklist checks can also help investigate suspicious IPs, domains, compromised infrastructure, abuse reports, and other threat-related signals outside email.
One listing is not the whole story
Different blacklist operators use different datasets and listing criteria. A target can be listed by one source and clean on another, which is why source-level results matter.
A minimal checker interface backed by a wide coverage matrix
The checker combines results from its active blacklist sources into one normalized response. Each source receives an explicit status, helping you distinguish a confirmed listing from a clean result or a source that could not complete the lookup.
16 active blacklist sources
The current coverage includes Backscatterer, Barracuda, Blocked Servers, EFnet RBL, GPF DNS Block List, ISX.fr DNSBL, InterServer IP List, JustSpam, NordSpam, PSBL, Plonkatronix, Spamhaus AuthBL, Spamhaus DBL, Spamhaus ZEN, Spamhaus ZRD, and USTC IP BL.
Structured results
Results are normalized into a consistent response structure rather than forcing you to interpret a different output from every source.
Source-level status
Results can return states such as listed, not_listed, error, and temporarily_unavailable.
Synchronous checks
The checker returns the final request/response payload directly, without requiring background jobs or polling.
16 active blacklists covered
Matches the published coverage list (live DNS lookups; Spamhaus DBL and ZRD evaluate the domain name directly).
| Source ID | Name | Checks IPs | Checks Domains | Reference |
|---|---|---|---|---|
| backscatterer | Backscatterer | ✓ | ✓ | Open source |
| barracuda | Barracuda | ✓ | ✓ | Open source |
| blocked_servers | Blocked Servers | ✓ | ✓ | Open source |
| efnet_rbl | EFnet RBL | ✓ | ✓ | Open source |
| gpf_dns | GPF DNS Block List | ✓ | ✓ | Open source |
| isx_fr | ISX.fr DNSBL | ✓ | ✓ | Open source |
| interserver | InterServer IP List | ✓ | ✓ | Open source |
| justspam | JustSpam | ✓ | ✓ | Open source |
| nordspam | NordSpam | ✓ | ✓ | Open source |
| psbl | Passive Spam Block List (PSBL) | ✓ | ✓ | Open source |
| plonkatronix | Plonkatronix | ✓ | ✓ | Open source |
| spamhaus_authbl | Spamhaus AuthBL | ✓ | ✓ | Open source |
| spamhaus_dbl | Spamhaus DBL (Domain Blocklist) | — | ✓ | Open source |
| spamhaus_zen | Spamhaus ZEN (SBL+XBL+PBL) | ✓ | ✓ | Open source |
| spamhaus_zrd | Spamhaus ZRD (Zero Reputation) | — | ✓ | Open source |
| ustc_ip_bl | USTC IP BL | ✓ | ✓ | Open source |
What Does Blacklisted Mean?
A listed result means the target matched the criteria of that particular blacklist source at the time of the check. A not_listed result means that the source did not identify a listing. Neither result should be treated as a universal reputation or security verdict.
listed
Listed
The source found a match for the checked value. Identify the source, investigate why the target may have been listed, and follow that source's remediation or delisting process.
not_listed
Not listed
The source did not report a listing during the check. Your target can still be listed elsewhere.
error
Error
The source did not return a normal result. Treat this as a failed lookup, not as a clean result.
temporarily_unavailable
Temporarily unavailable
The source was unavailable for a normal check at that time and should be checked again later.
How Do You Use the Blacklist Check API?
The Blacklist Checker API lets developers check IPs, domains, and URLs programmatically and receive structured JSON results. Requests are synchronous, so your application receives the response directly instead of creating a background job and polling for completion.
The API returns structured JSON containing overall status, target, target type, listing state, risk score, source counts, timestamp, latency, and source-level results.
Programmatic access: GET https://lookup.proweblook.com/api/v1/blacklistchecker (see API reference).
Accepted target types
ip checks raw IPs. domain and url both accept host values, and url is the safest option when callers may send full URLs like https://proweblook.com/faq.
Billing defaults
1 blacklist credit is deducted only for a successful structured response.
No deduction on invalid API key, invalid input, or hard system failure.
API Quick Reference
| Endpoint | GET /api/v1/blacklistchecker |
|---|---|
| Auth | API Key via query string — ?api_key=YOUR_KEY |
| Parameter | target — IP address or domain name |
| Response | JSON with blacklist presence and details |
Request example
GET https://lookup.proweblook.com/api/v1/blacklistchecker?api_key=YOUR_API_KEY&target=192.0.2.1&target_type=ip GET https://lookup.proweblook.com/api/v1/blacklistchecker?api_key=YOUR_API_KEY&target=example.com&target_type=domain GET https://lookup.proweblook.com/api/v1/blacklistchecker?api_key=YOUR_API_KEY&target=https://example.com/page&target_type=url&sources=spamhaus_zen,barracuda GET https://lookup.proweblook.com/api/v1/blacklistchecker?api_key=YOUR_API_KEY&target=8.8.8.8&target_type=auto GET https://proweblook.com/api/v1/check?api_key=YOUR_API_KEY&target=192.0.2.1&target_type=ip
Response example
{
"status": true,
"target": "proweblook.com",
"target_type": "domain",
"listed": false,
"risk_score": 0,
"listed_count": 0,
"not_listed_count": 16,
"error_count": 0,
"checked_at": "2026-08-17T23:46:15+00:00",
"latency_ms": 700,
"sources": {
"spamhaus_zen": {
"state": "not_listed",
"source_name": "Spamhaus ZEN (SBL+XBL+PBL)",
"source_url": "https://www.spamhaus.org/",
"matched_value": "",
"checked_value": "159.89.170.136",
"latency_ms": 203,
"data_age_sec": null,
"error": ""
},
"barracuda": {
"state": "not_listed",
"source_name": "Barracuda",
"source_url": "http://www.barracudanetworks.com/",
"matched_value": "",
"checked_value": "159.89.170.136",
"latency_ms": 214,
"data_age_sec": null,
"error": ""
}
},
"balance": 99
}
curl -X GET "https://lookup.proweblook.com/api/v1/blacklistchecker?api_key=YOUR_API_KEY&target=8.8.8.8"
const response = await fetch('https://lookup.proweblook.com/api/v1/blacklistchecker?api_key=YOUR_API_KEY&target=8.8.8.8');
const data = await response.json();
console.log(data);
import requests
url = "https://lookup.proweblook.com/api/v1/blacklistchecker"
params = {"api_key": "YOUR_API_KEY", "target": "8.8.8.8"}
response = requests.get(url, params=params)
print(response.json())
<?php $url = "https://lookup.proweblook.com/api/v1/blacklistchecker?api_key=YOUR_API_KEY&target=8.8.8.8"; $response = file_get_contents($url); echo $response; ?>
Simple, Transparent Pricing
Use the free blacklist checker for occasional IP, domain, and URL lookups, or move to paid blacklist credits when you need repeated or programmatic checks. The live anonymous demo currently allows 3 checks per day.
For higher-volume or API-driven workflows, choose from the available paid credit options below.
Flexible & Competitive Plans
Choose how you pay, pick your credit tier, and checkout with live Stripe or PayPal links.
Billing
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Explore the product now or contact us for the right allowance and pricing.
Enter your domain into the blacklist checker and run a domain check. The service evaluates relevant domain feeds and resolved IP addresses, then returns source-level results showing whether the domain or associated infrastructure is listed.
Enter the IP address into the checker and select IP as the target type. The service checks supported IP blacklist sources and returns a result for each source.
A blacklisted domain has been identified by one or more blocklist sources according to that source's listing criteria. The listing is a reason to investigate the source and the activity associated with the domain.
An IP can be listed because of spam activity, abuse, compromised infrastructure, suspicious traffic, or other behavior identified by a blacklist operator. The exact reason depends on the source that listed the IP.
Yes. Domain-based and IP-based blacklist systems can evaluate different signals. Some sources evaluate the domain directly, while others evaluate the IP address associated with the domain.
Yes. You can submit a full URL, and the checker normalizes the URL to its host automatically for the lookup.
No. A blacklist check only reports what the supported sources returned at the time of the check. A not_listed result is not a universal security guarantee.
Identify the source that listed the target, resolve the behavior that caused the listing, and follow that source's delisting process. The exact process varies by blacklist, and the checker does not remove third-party listings.
Delisting time depends on the blacklist operator, the reason for the listing, and whether the underlying issue has been resolved. Some sources update automatically, while others require a manual request.
Blacklist checks are generally performed against the sending IP or sending domain, not an individual email address. For email deliverability problems, check the infrastructure responsible for sending the messages.
A spam blacklist check looks for an IP address or domain on sources that track spam-related or reputation signals. It can help identify issues affecting email delivery, infrastructure reputation, or suspicious traffic.
Yes. The current coverage table lists Spamhaus AuthBL, Spamhaus DBL, Spamhaus ZEN, and Spamhaus ZRD among the active sources. DBL and ZRD evaluate domains directly, while ZEN covers IP-based checks.
Yes. Blacklist results can provide an additional signal for fraud, abuse, signup screening, and threat investigation workflows. They should be combined with other signals rather than used as the only factor in a fraud decision.
The current landing page supports a single target per check, and the documented API examples focus on individual targets. Bulk blacklist checking is not currently advertised as a supported endpoint.
Find Out Where Your IP or Domain Is Listed
Stop checking blacklist databases one at a time. Enter your IP, domain, or URL and get source-level results in one structured check. See which sources return listed, which return not_listed, and which need further investigation.
Use the blacklist checker for a quick reputation check, then investigate your IP intelligence or email infrastructure when the results point to a broader problem.
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