What incognito actually does
A private window starts with an empty cookie jar and discards everything when the last such window closes. History is not written, form entries are not saved, site data does not persist. That is the entire feature, and Chrome says so plainly on its own new-tab page.
It means someone else on the same device will not find the session afterwards. That is a genuine and often sufficient use: shared computers, a borrowed laptop, shopping for a gift.
What it does not do is make the traffic private. Every request leaves the machine identically, and your ISP, your employer’s network and the sites themselves see exactly what they would see otherwise.
What a VPN does that incognito cannot
It encrypts traffic between your device and the VPN server, so the network in between sees an encrypted flow to one address rather than a list of destinations. That covers the ISP, the café Wi-Fi and anyone monitoring the link.
It replaces the address sites see with the server’s. Combined with a private window’s empty cookie jar, that removes both the persistent identifier and the network-level one, which is why the combination is more useful than either alone.
What neither does
Neither logs you out of the internet. Sign into an account in a private window over a VPN and that account knows exactly who you are — no amount of network or local privacy survives you identifying yourself.
Neither defeats browser fingerprinting. Your fonts, screen dimensions, timezone, canvas rendering and installed extensions form a signature that persists across private windows and IP addresses. A VPN changes one input to that signature. The Tor Browser is the tool built for fingerprinting, and it works by making every user look identical rather than by hiding anything.
Neither prevents a site tracking you within a session. Incognito clears the jar when you close it; while it is open, cookies work normally.
Avoid
- Treating incognito as protection from an ISP or an employer — it is not, at all
- Treating a VPN as protection from someone with access to your device
- Assuming either gives anonymity once you have signed into an account
Using them together, sensibly
The combination is a reasonable default for anything you would rather not have persisted or observed: a private window handles the local side, the VPN handles the network side. There is no conflict and nothing to configure.
For anything stronger, the honest answer is that neither tool is the right one. A threat model involving a determined adversary needs the Tor Browser and a change of behaviour, not a subscription.