Browser profile isolation for multiple stores: what actually leaks

One profile per store is the usual advice. Here is what leaks between profiles even when you follow it.

The baseline

One browser profile per store, no shared accounts, separate payment instruments. That is the minimum. It is also not enough on its own — several signals are shared at the OS or network level, not the profile level.

What still leaks between profiles

1. The IP — if both profiles use the same exit address, they are linked at the network layer.
2. DNS resolver — same resolver, same country, often same operator.
3. Time zone and system locale — inherited from the OS unless the profile overrides them.
4. WebRTC — can expose local network interfaces that are identical across profiles.
5. Fonts and installed software — real hardware fonts are the same for every profile.
6. Canvas/WebGL renderers — often identical on the same GPU and driver.

What isolation does fix

• Cookies, local storage, sessions, history.
• Login state and passwords.
• Per-profile time zone and language overrides (in antidetect browsers).
• Per-profile proxy configuration.

A practical stack for two to five stores

• One antidetect browser, one profile per store.
• One dedicated static address per store (not a shared pool).
• A different payment instrument per store.
• A written record of which profile uses which IP.

What the platform sees

Two profiles on one IP with identical canvas and fonts look like one device with two accounts. Two profiles on two dedicated IPs with different proxies look like two independent sellers — which is what you want.

Where we fit

We check the network layer: whether the IP is really an ISP address, whether it changed, whether it is on a blocklist. The fingerprint panel shows what your browser exposes in the profile you are using right now.