One night I was fiddling with my proxy and clicked a WebRTC leak test almost by accident. I only wanted to confirm the proxy was on. The page showed my exit IP, and then, one line below, my local IP and the name of a city.
The city was where I live. I was sitting there with the air conditioner dripping behind me, and I suddenly felt cold.
What WebRTC is, in plain terms
It took me a while to understand. Browsers have a feature for video calls in web pages. To connect two people quickly, it asks your device "what network are you on" and shares that answer. It does not always care whether you have a proxy turned on.
So your page traffic goes through the proxy, but this little side road does not. Anyone who looks down that road sees where you actually are.
How I found it
The proxy I used was a browser extension. The switch was on, the icon was green, it said connected. And the WebRTC test still listed my real location. I did not believe it, so I tried a different test site. Same result.
I tried global mode. Also no. That was the night I learned that a lot of proxy tools only forward page requests, and WebRTC slips underneath them.
Things I tried
First, turning WebRTC off in the browser. Chrome does not give you a simple switch, so I installed an extension and edited flags. Half an hour later it was off, and so were my web meetings. I need those, so that path died.
Second, a browser that handles the problem for you. I ended up with an anti-detect browser that replaces the value. The test page then showed whatever address it decided to show. That worked, but it meant another app and another setup.
Third, the dumbest option: stop doing everything in one browser. Work, streaming, accounts, all separated. Now the browser I use for accounts does only that.
Why this matters for TikTok
At first I thought, so what, I am not doing anything wrong. Then my account kept having problems and I connected the two. The platform was not seeing "a user in the US." It was seeing "a user who claims to be in the US while the device is still sitting somewhere else." That contradiction is worse than just knowing where you are.
During that stretch my account asked for verification constantly and the feed was strange. After I fixed the environment and closed the hole, the prompts became less frequent. I cannot prove it was the cause, but the timing lines up.
My check now, every time
Turn on the proxy. Open the WebRTC test. Compare the region it reports with the exit IP. If they do not match, I do not log into anything.
I also glance at the IP lookup to confirm the exit is where I think it is. Two pages, under two minutes, much better than losing an account.
If you are using a browser-based proxy, go click that test page right now. A lot of people are not beaten by technology. They are beaten by believing they are already hidden.