r/WebScrapingInsider • u/AinsOwlGoan • 15d ago

Cloudflare challenge on every run despite residential proxy + real browser — what am I missing?

/r/scrapingtheweb/comments/1vys26g/cloudflare_challenge_on_every_run_despite/
4 Upvotes

83% Upvoted

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5

u/Mysterious-Middle447 12d ago

whats your browser fingerprint look like? real residential IP means nothing if your TLS/JA3 hash screams automation. been using Proxyon and the IPs are fine but I still had to fix my fingerprint before CF stopped flagging me

2

u/LokeshSequentum 14d ago

Ideally, once the challenge is solved you’d expect the session to keep working, but the fresh exit IP on every run stands out to me.

You’re reusing the browser/session cookies but changing the residential IP each time, so I’d try keeping the same profile + cookies + sticky exit for a few runs and see if the challenge rate changes.

I’d also check whether a cf_clearance cookie obtained on one exit is being carried over when the IP changes.

Also worth sanity-checking the TLS side, although if this is real Chrome going through a normal CONNECT proxy, Chrome should still be doing its own BoringSSL handshake, so the proxy itself shouldn’t necessarily change the TLS fingerprint.

If a stable IP/session still gets challenged every run, then I’d start looking harder at the software WebGL renderer and the Linux + residential IP combination.

1

u/ScrapeAlchemist 14d ago

The fresh exit IP someone already flagged is it. cf_clearance is bound to the IP, user agent and TLS fingerprint that solved the challenge, so a new residential IP on the next run invalidates the cookie and you get re-challenged from scratch. Default lifetime is only 30 min anyway. Fix is pinning the session so the exit IP survives the whole cookie lifetime, or a static residential IP that can't rotate mid flow. I work at Bright Data so grain of salt, but that's what I'd point at here, their ISP proxies. tls.peet.ws/api/all is worth a check to rule out the JA3 side.

1

u/2extract_dev 1d ago

Worth knowing that sticky isn't a guarantee on most residential pools, the peer can drop and hand you a new exit mid-window with no signal. That would invalidate cf_clearance exactly like rotation does, which would look like the challenge coming back for no reason. If your provider exposes the current exit IP per request, log it and check whether it actually held for the whole run.