If you run more than one store, ad account or social profile, you have probably seen it happen: one account gets flagged, and a week later the others go down with it. The platform decided they all belong to the same person.
Most of the time it is not anything you posted. It is the browser and the network giving you away. This guide explains the three signals that link accounts, and then walks through a setup that keeps each account in its own separate browser.
Before you start: many platforms limit how many accounts one person or business may run. Separate browsers are for running the accounts you are allowed to run without them bleeding into each other, not for getting around a platform's rules. Check the terms of each site you use.
Why accounts get linked
Websites do not need your name to know two accounts are related. They compare technical signals, and three of them do most of the work.
1. The IP address
Every request comes from an IP address. If two accounts log in from the same IP, or keep switching between the same few, that is the easiest link there is. A shared office or home connection is enough.
The location of the IP matters too. An account that says it is in Texas but always logs in from a server in another country looks odd.
2. The browser fingerprint
Even without cookies, a browser tells every site a lot about itself: the operating system and browser version, screen size, installed fonts, the graphics card (through WebGL and canvas drawing), the number of CPU cores, the time zone and the language.
Each detail is common on its own. Together they are close to unique, and they stay the same every time you visit. Two accounts opened in the same browser on the same computer share one fingerprint, so to the site they look like one device.
Mismatches are a signal as well. An IP in New York combined with a browser set to a Shanghai time zone and Chinese language is not what a real visitor in New York looks like.
3. Cookies and local storage
Cookies and local storage are how a site remembers you. Log in to account A, log out, log in to account B in the same browser, and the site can still read what it stored during the first session. Incognito windows only help until you close them, and they share one fingerprint anyway.
What this means in practice
To keep two accounts apart, each one needs:
- its own IP, ideally a stable one in the region the account belongs to,
- its own fingerprint, which stays the same every time that account is used,
- its own cookies and storage, never shared with the other accounts,
- a time zone and language that match its IP.
Doing that by hand with separate computers or virtual machines works, but it gets expensive and slow after two or three accounts. A multi-profile browser does the same job on one computer.
Setting it up: two separate profiles, one US and one Japan
The example below uses Nullprint (the walkthrough in the video takes about four minutes). We create two profiles: one with a US IP and one with a Japanese IP. Then we open Amazon in both and check that they really are separate.
Step 1: Add one proxy per account
You need one proxy per account. Any HTTP or SOCKS5 proxy with a username and password works; get them from whichever provider you already use.
In Nullprint, open Proxies, click Paste proxies, paste one proxy per line and click Add. Then click Check all. Each proxy shows Working with its exit IP and country, so you know where it really comes out before any account touches it.
The Shared filter at the top shows proxies used by more than one profile. For separate accounts you want that to stay at zero.
Step 2: Create a profile
Click New profile. Give it a name that tells you which account it belongs to, for example amazon-us. Leave the kernel and Chrome version as they are. The operating system matches your computer, which is the safest choice: a profile claiming to be Windows while running on a Mac is a mismatch of its own.
Step 3: Assign the proxy and let the environment follow it
Open the Proxy tab, choose From proxy pool and pick the US proxy. The panel on the left updates: the time zone and language now match the proxy's exit location. In the Fingerprint tab, time zone and language are set to Match IP.
You don't need to edit the fingerprint. It was generated to fit this computer and this proxy, and editing values by hand is the easiest way to create a combination no real device has. Click Create & lock fingerprint. From now on this profile reports the same fingerprint every time it starts.
Repeat for the second account with the Japan proxy. Each profile gets its own new fingerprint.
Step 4: Run a check-up before you log in
Select both profiles and click Check up. The check-up compares the exit IP, time zone, language and fingerprint and tells you if anything doesn't add up. Consistent means the profile is ready.
Do this again whenever you change a proxy, before logging in to anything.
Step 5: Launch both and verify
Click Launch on both profiles. Each opens its own browser window. Here the US profile opens amazon.com and sees a US delivery address and prices in dollars. The Japan profile opens amazon.co.jp and gets the Japanese site, a Japanese address and prices in yen. Neither is logged in.
Now the real test: open amazon.com in the Japan profile. It still offers delivery to Japan and knows nothing about what the US profile did. The two profiles share no cookies and no storage, so there is nothing for the site to connect.
Close the windows and launch them again: each profile comes back with its own cookies, the same fingerprint and the same IP.
A short checklist
- One account, one profile, one proxy. Don't share proxies between profiles.
- Keep the proxy in the account's region and keep it stable.
- Let the time zone and language follow the IP; don't set them by hand.
- Don't edit fingerprint values unless you know exactly why.
- Run the check-up after every proxy change, before you log in.
- Never log in to two accounts in the same profile.
About Nullprint
Nullprint is an AI antidetect browser for Windows and macOS: AI agents can run every profile through MCP. The Free plan gives you 5 profiles, free forever (new accounts start with a 7-day Team trial). More step-by-step guides: nullprint.ai/tutorials.
This post was drafted with AI assistance and reviewed by the Nullprint team.
Top comments (0)