You bought residential proxies, but your scraper still gets blocked. The IP looks clean on paper, but something leaks. It could be WebRTC. It could be a DNS mismatch. Or the “residential” IP might be a cheap proxy that’s actually a reused datacenter address.
Most detection checklists only check if the proxy works. They don’t check if it’s truly anonymous. Here is a residential proxy detection checklist that finds the hidden leaks.
Why detection matters more than speed
A fast proxy that leaks your real IP is worse than a slow one that hides it. If a target site detects your proxy, you waste time on requests that get blocked. You also risk IP bans that can hurt your account or project.
Detection isn’t just about websites. Some APIs and tools specifically flag proxies. If you use a proxy for Reddit , for example, the platform uses multiple signals to detect residential proxy traffic. One leak is enough to get your account suspended.
Step 1: Verify the IP is residential, not a datacenter proxy
Some providers sell datacenter traffic as “residential.” Run the IP through a classification service like ipinfo.io or a simple WHOIS lookup. Residential IPs are assigned to internet service providers for home users. Datacenter IPs belong to cloud providers like AWS or DigitalOcean.
If the WHOIS record shows an ISP like Comcast or Verizon, you are likely safe. If it shows “Amazon Technologies” or “Google Cloud,” you have a datacenter proxy, not a residential one.
Step 2: Test for WebRTC leaks that reveal your real IP
WebRTC is a browser feature that can expose your real IP even when you use a proxy. Go to a WebRTC leak test site like browserleaks.com. If you see your ISP-assigned IP instead of the proxy IP, your real address is leaking.
To fix this, disable WebRTC in your browser or use a dedicated proxy tool that blocks it. Many users skip this step and wonder why they get blocked immediately.
Step 3: Check DNS leaks that bypass your proxy entirely
DNS leaks happen when your device sends DNS queries directly to your ISP instead of through the proxy. Use a DNS leak test website. If the detected DNS server belongs to your local ISP, your proxy setup is flawed.
Most residential proxy providers include DNS routing. But if you configured the proxy manually, you might have missed this. A DNS leak makes your traffic look like it comes from two different locations, which is a common detection pattern.
Step 4: Run a blacklist check on your proxy IP
Even a real residential IP can be blacklisted if it was used for abuse before you got it. Use a free blacklist checker. If the IP is listed in any major blocklist, your requests will fail.
This is especially important if you need a proxy for scraping. Many e-commerce sites and social platforms maintain internal blocklists that overlap with public ones. A blacklisted IP is a dead end from the start.
Step 5: Test proxy detection with a real target site
Do not trust generic tests. Visit the actual site you plan to use and check if it blocks you. Some sites like Amazon or Reddit use custom detection logic that generic tests miss.
Open your browser’s developer tools. If you see a 403 or a CAPTCHA on your first request, your proxy is detected. Try a different IP from the pool. If all IPs get blocked, your provider’s pool is flagged.
Step 6: Validate geo-targeting accuracy
Residential proxy detection sometimes fails because the geo-location is wrong. If your target expects a New York IP but your proxy shows Chicago, the site may flag it as suspicious.
Use a geo-location API to confirm the city matches your target. If the location is off by hundreds of miles, the proxy is either misconfigured or the IP was reassigned recently.
Common mistakes that make your proxy detectable
- Using the same proxy IP for multiple accounts. This always triggers a fraud flag.
- Forgetting to clear cookies and cache between sessions. Old data links your new proxy to your old identity.
- Testing only once. Detection patterns change, and a clean IP today may be flagged tomorrow.
- Ignoring user-agent strings. A residential proxy with a datacenter-style user agent is a giveaway.
Mini scenario: The Reddit scraper that got banned in 30 minutes
A team bought a residential proxy pool to scrape subreddits. The first 20 requests worked. Then all accounts got banned. They ran this checklist after the fact.
Step 1 showed the IPs were residential. Step 2 found WebRTC leaks. The proxy tool had not blocked the browser’s WebRTC feature, so every request sent the real IP alongside the proxy IP. Reddit detected the mismatch and banned all accounts.
They fixed the WebRTC issue, rotated IPs, and the scraping worked for weeks. One leak was enough to ruin the project.
For this use case, recommended proxy provider should be compared by pricing, setup difficulty, support quality, refund policy, and whether it fits your workflow.
FAQ
Q: How often should I run a residential proxy detection checklist?
A: Run it once when you set up the proxy, then weekly if you use a rotating pool. IPs change, and new leaks can appear after browser updates.
Q: Can a residential proxy be detected even if all tests pass?
A: Yes, if the target site uses behavioral detection. A proxy that passes technical tests may still be flagged if the request pattern is unnatural. Use random delays and realistic request volumes.
Q: What is the most common leak in residential proxy setups?
A: WebRTC leaks. Many users do not know their browser exposes the real IP, and proxy tools often do not block it by default.
Q: Is a datacenter proxy always worse than a residential proxy?
A: For scraping, yes. Datacenter IPs are easier to block. For casual browsing, a cheap proxy from a datacenter may work fine if the site has weak detection.
Q: Do I need a different checklist for each target site?
A: Yes. Amazon, Reddit, and Google each use different detection methods. Test against the specific site you plan to use.
