Does restarting my router guarantee a new public IP?

Restarting a router does not force your internet provider to assign a different public IP address. The provider may retain or reassign the same address, depending on how its service allocates addresses.

Does changing my public IP also change my device's MAC address?

Changing your public IP address does not by itself change the MAC address used by your device's WiFi or Ethernet interface. Features that use a private or randomized WiFi MAC address operate separately from public IP assignment.

Do temporary IPv6 addresses hide my network prefix?

Temporary IPv6 addresses change the interface identifier portion of an address while using a network prefix assigned to the connection. The prefix may stay the same across several temporary addresses, allowing an observer to associate traffic with the same network.

Do two Incognito windows have separate cookies?

In Chrome, opening another Incognito window within the same browser profile continues the existing Incognito session, so the windows can use the same session cookies. You must close all of that profile's Incognito windows to end the session.

Can a saved link identify me after my IP changes?

A saved link may contain an identifier that a service can recognize when you follow the link, regardless of your new IP address. Some link parameters identify a particular recipient or visit, while others only identify a shared advertising campaign.

Does changing DNS servers clear tracking cookies?

Changing DNS servers affects the service used to look up domain names, not the cookies stored in your browser. To remove those cookies, use the browser's cookie or site-data controls.

Is clearing the browser cache the same as clearing cookies?

Clearing the browser cache removes stored copies of page resources, such as images and scripts. Cookies are a separate data type, so selecting only cached files when you clear browsing data normally leaves cookies in place.

Can a browser update change my browser's fingerprint?

A browser update can change the reported version and other behavior that a website observes. A site may still be able to link visits before and after the update using characteristics that remain unchanged.

Does HTTPS stop a site from receiving tracking cookies?

HTTPS encrypts the connection, but the receiving website can still read cookies that your browser sends with its requests. Encryption protects those cookies in transit; it does not prevent the intended recipient from using them.

Does Do Not Track automatically block tracking?

Do Not Track is a browser preference that asks websites not to track you. Its specification was discontinued, and sending the signal does not block requests or delete cookies.

Does Changing Your IP Address Stop Online Tracking?

Changing your IP address does not automatically stop online tracking. It changes the network address a website can see, but it does not clear your browser's cookies or delete records held by a service. A website may still connect your visits through an account, an existing browser session, or details about your browser and device.

The effect depends on how the site recognizes returning visitors. A site that identifies visitors only by IP address may no longer link your new requests to your earlier visits. A site where you remain signed in can still link activity to your account.

What a New Public IP Changes

Switching from home WiFi to mobile data often changes the public IP used for your internet connection. Your internet provider may also assign a different address, and websites usually see a VPN server's public address for browsing traffic routed through that server. Connecting to a VPN does not change the address seen by a website if that website's traffic bypasses the tunnel.

A new public IP may change a site's estimate of your location or affect an address-based request limit. It can also prompt an account security check, including a request to sign in again. These changes do not prove that the site treats your visit as unrelated to earlier activity.

Public IPv4 addresses can be shared by people in one household or, through a provider's address translation, by several customers. The private IPv4 address your router assigns to a device, such as 192.168.1.23, has a different role. Changing that local address alone does not change the public address used by the router or provider to send traffic to a website.

Cookies and Accounts Can Link Visits

A cookie is a small piece of data a website can store in your browser and receive again on later requests, depending on the cookie's scope and your browser's settings. Cookies can hold preferences, maintain a shopping cart, or carry an identifier for a login session. Changing your IP does not remove those cookies.

If your browser sends a valid login identifier and the service still accepts it, your account session can continue after an address change. Signing into the same account again also gives the service a direct way to associate the new activity with that account. Recognizing an account or browser session is not, by itself, proof of who is using the device.

Clearing cookies and other site data can remove identifiers stored locally and may sign you out. It does not delete a website's own activity logs or account history, and signing out does not necessarily remove every cookie. A service's mobile or desktop app can also stay signed in when you clear data in your web browser.

How Tracking Works across Websites

Recognizing a returning visitor on one website is different from linking that visitor's activity across several sites. A page can load advertising or analytics resources from another company. If that company receives the same identifier when its resources load on different websites, it may be able to connect those visits even after the visitor's IP changes.

Browsers can block third-party cookies or keep a third party's cookies separate for each website you visit. Those restrictions make it harder for third parties to link visits across sites, but a website can still recognize an account you sign into.

Browser Characteristics Can Persist

Websites can receive or request details such as your browser version, language settings, and screen dimensions. Combining several observable details can sometimes help distinguish one browser from others, a technique known as browser fingerprinting. Changing your IP alone does not change these properties.

How well a fingerprint distinguishes your browser depends on which details a site can access, how common those characteristics are, and the browser's privacy protections. Browsers may limit exposed information or block known fingerprinting scripts. Even when details match, they do not necessarily identify a particular person. A website might recognize you after an IP change because you are still signed in or the browser sends a stored cookie. Recognition alone does not prove that the site used fingerprinting.

What Private Browsing Changes

Private browsing starts a temporary session that does not use cookies or site data from your regular windows. In Firefox, cookies created during that session are stored separately and discarded when the private session ends.

A private window does not hide your public IP from websites or stop a site from collecting information during the visit. If you sign into an account there, the service can associate activity with that account. Private browsing also leaves downloaded files on your device, even after the session ends.

Ways to Reduce Tracking

Choose privacy settings based on whether you want to limit what the browser saves on a shared computer, reduce tracking across websites, or manage data held by a service. Each task involves different controls:

Sign out of the website if you do not want later activity linked through that account session. Cookies and other identifiers may still let the site connect later visits.
Review which cookies and site data your browser will clear, including any selected time range. Deleting cookies and site data can reset preferences or sign you out, so select only the sites and data types you intend to clear.
Check your browser's tracking protection and third-party cookie settings. Review exceptions for individual sites, since those exceptions may allow content or cookies that would otherwise be blocked.
Use separate browser profiles when you need separate local sessions, such as keeping work and personal accounts apart. Signing into the same website account in both profiles still links activity to that account.
Check the service's privacy settings to see what account data you can review or delete. Deleting data from your browser and requesting deletion from a service are separate actions.