Why did my proxy stop working while my home IP kept working?
Because the two IPs were not equally trusted, and trust is the whole variable. A site does not block "proxies" as a category. It blocks specific IP addresses and ranges it has learned to distrust, and if your home connection and your proxy sit on different reputations, they will get different outcomes even against the exact same request. One scraper described this on Reddit almost exactly: scraping through a proxy had stopped working on a site that used to be scrapeable, while their home residential IP was fine, and they weren't sure if it was blacklisted IPs or something else. That "something else" is usually IP quality, not proxy type.
What actually makes an IP "low quality"
An IP's quality is a history, not a label. It's built from a few concrete things a site (or a fraud-score database) can check.
- Abuse history. The address was previously used for spam, credential stuffing, ad fraud, or scraping that got reported. Fraud-score services and blacklist databases (Spamhaus-style lists, IPQS, proxycheck-type tools) keep records of this and score the address accordingly, independent of who is using it now.
- ASN and connection type. Every IP belongs to an Autonomous System Number, and that ASN is labeled as residential ISP, mobile carrier, hosting/datacenter, or VPN. Sites that fingerprint aggressively weight datacenter and known-VPN ASNs far more suspiciously than residential ISP ASNs, because a real household is less likely to be running a bot.
- Concurrency and reuse. The same IP handling many simultaneous sessions, or being reused across a large number of unrelated accounts in a short window, is itself a signal. A residential IP used the way an actual residence uses it looks nothing like a residential IP used the way a proxy pool uses it, and that pattern is detectable from the request side even without checking a blacklist.
- Geographic mismatch. An IP that geolocates somewhere the account or session has never logged in from before is a mismatch signal, separate from whether the IP itself is "clean."
None of these are permanent. An IP that was clean last month can get burned this month if enough traffic through it triggers abuse reports. Sites also just get more aggressive over time, independent of anything you did.
Is a residential IP automatically clean?
No. Residential versus datacenter versus mobile describes the connection type, not the individual address's current reputation. A residential ASN lowers the baseline suspicion a site applies, but a specific residential IP can still be flagged if it has abuse history, is being hit with unusually high concurrency, or has been reused across too many accounts. This is the mistake in treating "I have residential proxies" as a solved state. Residential is a category that tends to score better. It is not a guarantee that a specific IP is trusted right now.
Why does IP quality change without me doing anything?
Because the target site's fingerprinting gets more aggressive over time, and because pooled IPs get used by other sessions you don't control. One commenter, describing coming back to sneaker botting after a break, put it directly: assuming the proxy game is the same as before is the mistake, because retail sites have gotten way more aggressive with fingerprinting over the past year or so, and IPs that used to pass now get flagged faster. Not a claim about any specific provider. Just a description of how anti-bot systems evolve on a longer timescale than most people re-check their setup.
How much of "my bot isn't working" is actually the proxy?
A meaningful share, but not all of it, and conflating the two wastes time debugging the wrong thing. One experienced scraper framed it as roughly 30% the bot itself and 70% the rest of the setup, including proxies, server speed, task concurrency, and whether the payment or account profiles behind the requests are clean. IP quality sits inside that 70%. If the bot logic is correct and requests still fail, the fastest thing to rule out isn't the code. It's whether the IP making the request is one the target site already distrusts.
How do I actually check an IP's quality instead of guessing?
You run a real fraud-score check on it rather than assuming based on "residential" or "datacenter." BirdProxies runs a free tool at /tools/ip-fraud-score that checks any IP (including whatever IP you're currently sending requests from) and reports its connection type, whether it shows up as a known proxy, VPN, or Tor exit, and a 0-100 risk score built from that fingerprint data. It's a live check, not a cached label, which matters given that quality changes over time. Check the IP before you build automation on top of it, and check it again when something that used to work stops working, instead of assuming the proxy type alone tells you the answer.
What keeps an IP's quality high over time
Three habits do more than any single IP choice.
- Match rotation cadence to the site's tolerance. A site with light fingerprinting tolerates a slower rotation; a site with heavy bot detection wants a fresh IP more often. Rotating faster than needed burns pool depth for no reason, rotating slower than needed lets a single address accumulate the request volume that gets it flagged.
- Don't overload one address across sessions or accounts. The concurrency and reuse pattern described above is one of the more detectable signals, so spreading unrelated accounts and heavy concurrent sessions across separate addresses keeps any single IP's footprint looking ordinary.
- Pick the connection type the site actually fingerprints against. For sites that check ASN aggressively (ticketing, retail checkout, social platforms), residential or ISP addresses start from a better baseline than datacenter. For high-volume scraping where the target isn't fingerprinting hard, datacenter bandwidth can be the more efficient choice. The right type is a function of what the target checks, not a universal ranking.
Frequently asked questions
Does "residential proxy" mean the IP is guaranteed clean? No. Residential describes the ASN and connection type, which lowers baseline suspicion, but any individual residential IP can still carry abuse history or high-concurrency signals that get it flagged. Check the specific IP rather than assuming based on category.
Can an IP that worked yesterday get flagged today? Yes. Abuse reports, unrelated traffic through the same pooled address, and the target site tightening its own fingerprinting can all change an IP's status without any change on your end.
What's the difference between an IP blacklist and a fraud score? A blacklist is a binary flag from a specific database: this IP is known-bad. A fraud score, like the one from IPQS-style checks, is a computed risk value from 0-100 built from multiple signals (ASN, proxy/VPN/Tor detection, abuse history), so it can catch risk even on an IP that isn't on any blacklist yet.
Does high concurrency on one IP actually get detected? Yes. A site can observe the pattern of many simultaneous sessions or rapid account switching from a single address regardless of whether that address is otherwise clean, and that pattern alone is a commonly used detection signal.
Is datacenter always worse than residential for avoiding blocks? Not universally. It's worse specifically against sites that fingerprint ASN type aggressively (ticketing, retail, social). Against targets that don't weight connection type heavily, datacenter's speed and cost can make it the better fit.
How do I check the fraud score of an IP I'm already using? Use a live fraud-score tool, such as /tools/ip-fraud-score, which checks the IP's current connection type, proxy/VPN/Tor detection, and 0-100 risk score at the time you run it, rather than relying on a static assumption about the IP type.