Cookies and site data are remembered while you're browsing, but deleted when you exit Incognito mode. You can choose to block third-party cookies when you open a new Incognito window.
Every time you close an Incognito window and open it again, it automatically clears any cache and cookies from the previous session without affecting your regular browser windows.
The first thing to recognize is that Incognito mode is not cookie-less nor cache-less. Once you open an Incognito window, those cache files and cookies are created and will remain until the Incognito browser is closed.
Remember, incognito mode only prevents your browsing history from being visible to other people who use your device. Incognito history and data are automatically deleted from your browser — so you don't need to clear your browser history manually. But, incognito history data is still stored on your device.
Private browsing provides some protection against cookie-based tracking. Since cookies from your private browsing session are not stored after you close your private browsing window, it's less likely that you will see online advertising in the future related to the websites you visit while using private browsing.
And speaking of Incognito sessions, all cookies and site data are automatically cleared after ending one in Chrome. However, users can adjust their settings to enable cookies in Incognito mode if they wish. Users can also: customize the sites for which they want to enable cookies.
Incognito mode doesn't stop web tracking. Your ISP, your employer, the websites you visit, search engines, the government, and other third-party snoopers can still track your browsing even if you use incognito mode.
Incognito mode doesn't save your browsing history, cookies, or other site data. But your device saves your browsing session in its domain name system (DNS) cache even if you use private browsing mode.
If there's something you don't want to keep in your browser history, like shopping for a gift for a relative, an incognito search can keep your activity private. It's also a good idea to use incognito mode when using a public device or a borrowed computer to protect your data.
Prevents some forms of internet tracking: After completing a browsing session using incognito mode, your browser will clear cookies from your device. This can help prevent companies from tracking you and may limit your exposure to targeted ads and dynamic pricing.
Incognito or private mode will keep your local browsing private, but it won't stop your ISP, school, or employer from seeing where you've been online. In fact, your ISP has access to all your browsing activity pretty much no matter what you do. You can, however, use a Virtual Private Network (VPN) service.
You can find the cookies in the Developer Tools, in the Resources (now Application) tab, even in an Incognito window. Open them with: F12 on Windows.
The data in your cache builds over time and can end up slowing things down if it becomes too bulky or out of date. (My phone had about 150MB of data stored in Chrome when I checked.) Clearing that data gives sites a fresh start, which may fix some loading errors and speed up your browser.
Tip: Clearing the cache simply clears temporary files. It won't erase login credentials, downloaded files, or custom settings.
Tip: Incognito mode, and Safari's private browsing mode, don't store browsing data. If you were browsing in a regular tab, your history would be recorded. You can delete it manually, but while it's easy to do for history, it's much trickier to remove cookies and other cached data manually.
He may not want you to see what websites he's visiting, he may not want others to see what websites he's visiting, or he may just be using the mode for privacy purposes. Whatever the reason is, it would probably be best if you asked him directly instead of trying to guess.
Deleting your browsing history is like deleting your email's “Sent” folder. On your end, it's gone, but the information has already been sent. Your information is on the WiFi owners' router logs, even if you have cleared it on your end.
Using a Privacy-Focused Search Engine
A privacy-focused search engine like DuckDuckGo or StartPage can help you keep your browsing history private. These search engines do not track your activity or store your search history, so your Wi-Fi owner cannot see what you've been searching for.
While incognito mode discards your search history from your computer, it doesn't hide your IP address. Websites can still see your IP address, browser, browser's settings, operating system (OS), and even your internet searches. Basically, you get security and privacy on your computer only.
Cons of incognito mode
While browsing incognito, unless you take additional steps to encrypt your data and internet connection, your IP address remains visible and other people on your network can see your online activity.
Incognito mode does not hide your IP address, doesn't prevent your activity from being tracked by third parties online, and it doesn't protect you from malware. Your information is still exposed, even while private browsing in Chrome.
Is a VPN better than incognito mode? A VPN is better than incognito mode because it encrypts all of your web activity data and device IP address from everyone except the VPN provider itself, including your internet service provider (ISP).
To answer your question though, no, ISPs will not include any actual usage information on a bill other than the amount of data used in some cases. Even on mobile plans, where data limits apply, you will often only see bandwidth numbers if you have overage charges.