Why IP Cleanliness Matters and How to Verify It

IP address cleanliness is critically important when you need unobstructed access to web resources, zero risk of blocks, and successful email deliverability. In today's article, we'll break down what clean IPs actually are, what parameters determine their reputation, and which addresses should never be used to avoid anti-fraud filters.

What Is a "Clean" IP and Why It Matters

A clean IP is an address with a positive network reputation that doesn't appear on spam lists and hasn't been used for fraudulent activities.

Any clean IP addresses will meet several criteria:

1. Absence from blacklists (DNSBL, RBL). This is the basic level of digital hygiene. If an IP becomes dirty, it typically ends up in public blacklists (Spamhaus, Barracuda, etc.). This is the primary indicator that the address was used for spam distribution and other malicious activities.
2. Low Fraud Score / Reputation Score. Anti-fraud platforms (such as Scamalytics, IPQS, MaxMind) assign a risk score to every address. A clean IP has minimal scoring, close to zero, indicating a high degree of trust.
3. No history of abuse. It's important to consider not just the current state but the address's past. If phishing attacks, brute-force attempts, or spam distribution were previously recorded from this IP, its reputation will be considered questionable even after changing owners.
4. Correct geolocation and ASN. A clean IP should belong to the address claimed by the internet provider. For example, if checkers show that an address belongs to a provider in Germany, but the geolocation fluctuates between the Netherlands and Russia—this is a serious signal for anti-fraud systems.
5. No association with proxies, VPNs, and datacenters. An ideal address should not be identified as a VPN, Tor node, public proxy, or datacenter server; otherwise, the IP's cleanliness will be questioned by anti-fraud systems.

Preliminary IP cleanliness checks will facilitate further work:

• Passing verification on platforms. An IP address identified as belonging to a VPN or datacenter will complicate registration on Google, Facebook, or Amazon. And even if verification is successful, there's no guarantee you won't be blocked in the future.
• Avoiding captchas and other additional checks. If an IP belongs to a database of suspicious addresses, you'll regularly waste time passing checks, repeatedly selecting traffic lights and fire hydrants in images. Clean IPs, however, don't encounter such obstacles.
• Stable account operation. Most bans and blocks are related to previous suspicious activity from an IP address. Clean IPs are a guarantee of long and stable account existence, whether it's a profile on a crypto exchange or a Facebook account.
• Trust from anti-fraud systems. Modern anti-fraud systems operate based on behavioral analysis and reputation databases. They don't just block obvious violators but also assign their own trust coefficient. A clean IP receives high trust, allowing sensitive actions (fund withdrawals, payment data changes, and launching ad campaigns) without triggering additional checks.
• Email deliverability and indexing. In email marketing, IP cleanliness is critical: sending email campaigns from a spam-tainted address may not even get started, or all messages will go straight to the "Spam" folder. For SEO specialists, a "dirty" address means constant captchas and bans for parsers and other working tools.

Where "Dirty" IP Addresses Come From

Every server marked by anti-fraud systems received its "black mark" for specific negative actions. These can be divided into four main groups.

Usage History

This is the most common and widespread reason for an IP address to end up on a blacklist. Here's what might be inherited by a new server owner:

• Spam distribution
• Phishing campaigns
• Brute-force attacks
• DDoS attacks
• Compromises in data breaches, etc.

AbuseIPDB, Spamhaus ZEN, haveibeenpwned, and other projects providing access to databases of fraudulent IPs collect and store data for years. If an address was flagged in unreliable activities, this history cannot be erased.

Subnet Type

Anti-fraud systems look not only at the specific IP but also at its environment — the entire subnet to which it belongs. If many violations are recorded in a range, everyone suffers. This is especially relevant for shared proxies: if one user from the pool spams or engages in brute-forcing, the reputation of the IP address as a whole drops, including for everyone using it.

Regarding datacenter proxies, they are often detected and banned by anti-fraud systems preemptively: due to their low price, such addresses are used by spammers and fraudsters.

Improper Configuration

An IP address might be initially clean, but errors in its configuration settings can lead to critical consequences. Here are the most common scenarios of proxy conflicts with platforms.

Typically, anti-fraud systems check the digital fingerprint of the device when verifying users. Any mismatch between IP, DNS, timezone, browser language, OS version, and other parameters lowers the trust rating, even if the IP itself is formally clean.

Automatic Blocks

Even a perfectly configured IP can be "contaminated" by your own actions. Platforms track not only technical parameters but also behavior patterns. If behavior differs from typical user behavior, the system marks the IP as suspicious.

The following negatively impact IP cleanliness:

• Multi-accounting. This is a red flag for any major platforms: even if formally creating multiple accounts by one user isn't prohibited, for the system this is a powerful trigger for verification. Account connectivity is detected through identical browser fingerprints, which compromise "dirty" IPs.
• Suspicious activity. Filling out a registration form in seconds, clicks with identical intervals, instant page transitions without pauses for reading content, and scrolling pages at the same speed indicate automated behavior.

When anti-fraud systems see such scenarios, atypical for ordinary users, they immediately flag the account for additional verification.

Key Parameters for Checking IP Cleanliness

Even the most reliable providers sometimes sell addresses with questionable histories. Fortunately, you can independently verify IP cleanliness.

Blacklist Checking

First, we'll go through public databases of "dirty" IP addresses flagged for spam distribution, phishing, and other abuses. There are quite a few on the market, and each database operates by its own criteria.

You can check for IP presence in spam databases through:

• multi.valli.org — checks against 80+ RBLs for free;
• mxtoolbox.com — checks against 100+ lists, saves check history;
• talosintelligence.com — shows IP reputation in the Cisco ecosystem;
• dnsbl.info — niche RBL checker.

Ideally, an IP address shouldn't be in any of the known lists. If it appears in one of the secondary databases, this is a warning sign; its presence in Spamhaus or Barracuda is an outright red flag.

Fraud Score / IP Reputation

Next, we move to fraud rating — this is an assessment of the probability that an IP is used for fraud, even if it's not in blacklists. The final Fraud Score is formed based on many factors, including:

• IP history;
• Subnet type;
• Anomalous behavioral factors, etc.

Top services for checking fraud rating include:

• IPQualityScore (IPQS): up to 5,000 requests per month can be made for free;
• Scamalytics: has a limited free quota;
• IPVoid: completely free service;
• AbuseIPDB Confidence Score: also works for free.

Checking an IP for cleanliness can yield different results; here's the generally accepted Fraud Score scale in the industry:

• 0-15 — excellent, the address can be used for any platforms
• 15-40 — risky, increased probability of captchas and additional checks
• 40-70 — high probability of blocks, not recommended for use
• 70-100 — almost 100% chance of blocking, the IP has a dirty history

Ideally, it's better to check an address through different services to get an averaged rating based on several values.

Network Type and ASN

Anti-fraud systems always look at who owns the IP. Even if it's clean by RBL standards and has a low Fraud Score, its network type can be a reason for blocking. The same applies to ASN — the autonomous system number, i.e., the identifier of the network to which this address belongs.

Here are several services that will help check IP cleanliness by ASN and network type:

• ipinfo.io: shows ASN, organization, and network type;
• IP2Location: identifies datacenters, proxies, VPNs, and Tor;
• Whoer.net: shows ASN and provider registration country;
• bgp.he.net: detailed ASN information — owner and network ranges.

If, as a result of checking, addresses are displayed as datacenter-based, this is again a red flag: such IPs will be automatically blocked on most platforms.

Geolocation and Compliance

Here's what a typical anti-fraud system looks at:

• Country — IP should belong to the GEO where the user is located;
• City — desirable but not critical match (difference of 50-100 kilometers is acceptable);
• Timezone — should correspond to the IP's region;
• Provider — ISP name should correspond to the country and network type.

Services from the previous point also check addresses for geolocation compliance with real parameters. Note: variation in IP location isn't yet a critical remark, but discrepancy between countries for the address and user geolocation is an obvious sign of proxy or VPN for anti-fraud systems, which may subsequently lead to blocking.

Proxy / VPN / Tor Detection

For platforms with strong anti-fraud systems, this is probably the most important parameter: if an address is identified as a proxy, even IP cleanliness won't help.

We need to find out during checking:

• Whether the IP is used for a proxy server (HTTP/SOCKS);
• Whether the IP is a VPN server (OpenVPN, WireGuard, etc.);
• Whether the IP belongs to a Tor node (exit node);
• Whether the IP is in public proxy lists.

You can check IP cleanliness and non-compliance with address spoofing tools through:

• Pixelscan.net — specialized tool for detecting proxies and bots, shows user digital fingerprint and WebRTC leaks;
• Whoer.net — VPN/proxy detection, anonymity check;
• BrowserLeaks.com — a whole set of leak tests, including WebRTC, DNS, JavaScript;
• IPQualityScore — gives an accurate answer whether an IP belongs to proxy, VPN, or Tor, determines network type.

Speed and Ping

This is an indirect but important parameter characterizing clean IPs. High ping can cast suspicion on all user traffic, while speed fluctuations can be identified as a sign of cheap proxies.

Check your server's connection speed through:

• Speedtest.net — download/upload speed, ping;
• Ping.pe — ping from multiple points worldwide;
• Ipinfo.io — basic ping (within free access limits).

Based on check results, you can evaluate the IP:

Low connection speed isn't always a risk factor for anti-fraud systems. But instability indirectly indicates connection through proxy or VPN. Besides, it's simply inconvenient when performing work tasks on accounts.

Step-by-Step Guide: How to Check IP Cleanliness Yourself

You already know how IP cleanliness is determined, so it's time to break down in practice how to check it step by step.

Step 1: Basic Check

First, you should go to 2ip.ru or whoer.net. We're interested in the following parameters:

• GEO (does it match what we're checking);
• Provider (not a datacenter);
• Language and timezone (match the IP);
• VPN and proxy detection (not detected);
• Anonymity (low — this is a sign of an ordinary user).

Obviously bad IP addresses will be eliminated at this stage.

Step 2: Blacklist Check

Two services will suffice here, and the first is abuseipdb.com. Open the site, enter the IP in the search bar, and analyze the results:

• Abuse Confidence Score — should be up to 10%;
• Total Reports — number of complaints (ideally there shouldn't be any at all);
• Last Report Date — date of last complaint (a warning sign if they were within the last month);
• ISP / Usage Type — home provider or mobile network, not a datacenter.

Next, mxtoolbox.com will help us. Check the IP address there and evaluate the output:

• All lists green — excellent, the address doesn't belong to any blacklists;
• One or two yellow lists — if it's Spamhaus or Barracuda, reject the IP;
• Several red lists — definitely don't use this address.

Step 3: Fraud Score and Reputation

To check the fraud rating, go to Scamalytics.com. Enter your IP and get the following data:

• Fraud Score — ideally up to 15, an IP with a score above 40 is considered "dirty";
• Risk Level — we need low, medium will work in some cases;
• Proxy/VPN/Tor Detection — discard the IP if it fails any of these checks.

The main check at this point is, of course, the Fraud Score. For additional checking, you can go to ipqualityscore.com to see, in addition to the fraud rating, whether there were complaints about the address in the last 30 days.

Step 4: Leaks and Fingerprints

By this point in the list, only completely clean IPs remain, but it's worth making sure they have no technical problems. The following services will help with checking:

• BrowserLeaks.com checks WebRTC leaks for revealing the real IP address, matching the visible IP with the checked one, DNS leaks, and browser fingerprint in general. Failing the check on at least one of these parameters is a reason to change the address.
• dnsleaktest.com shows DNS leaks. We're satisfied with a result where only DNS servers from the IP's country are shown. If they belong to a different GEO, for example, where you're physically located, there are leaks, and the real address is revealed.
• pixelscan.net — comprehensive anonymity check. Scanning takes 10-20 seconds and reveals all possible problems that will complicate further work with this IP. Pay special attention to markers for bots, proxies, VPNs, and datacenters. The tool also shows IP reputation—if it determines it as low, it's better to change the connection.

Step 5: Check on Specific Platforms

The final step is checking the IP in action:

1. Open the platform you plan to work with (Gmail, Facebook, Binance, etc.)
2. Try to create a new account.
3. Evaluate the result using the table below:

Once the account is successfully created, let it sit and check back in a few hours. A block in the near future will indicate that the IP cleanliness check wasn't passed after all. Repeated captcha occurrences are a warning sign: you can work with the profile, but it's better to prepare backups immediately.

Conclusion

Investments in clean IPs aren't a whim but an investment in stability and work success, which will directly pay off through account preservation. IP reputation can change at any moment, so regular checks should become the norm. Use the step-by-step guide from this article to test your IPs today — it will take no more than 10 minutes but will save hours on solving problems with anti-fraud systems in the future.