One Request, Five Observers: What Websites, Providers, DNS and VPNs Learn When Loading a Page

The phrase “I have HTTPS, so my provider sees nothing” sounds convincing until one asks what exactly counts as “nothing.” Site name, specific article, message text, external IP, account, browser language and connection time are different data points that appear at different points along the route and reach different parties. This turns most privacy debates into exchanges of half-truths.

Consider an ordinary request to https://news.example/articles/privacy?from=mail from a home connection, standard browser and correctly configured HTTPS site. Corporate networks, antivirus products that replace certificates and decrypting proxies are separate cases where the network administrator can see more.

Browser knows the full address before any packet is sent

Before the first network packet leaves, the browser already possesses the complete URL, including path and query parameters, plus any stored state such as cookies, site data and login tokens. It applies strict rules when deciding what to send to each origin. Scripts on the page can read language, timezone, screen size and graphics API results, yet localStorage remains isolated by origin, HttpOnly cookies stay invisible to JavaScript, and the site cannot enumerate all open tabs or full history.

DNS resolver learns only the domain name

To reach the server the browser must resolve the domain. An unencrypted DNS query can be observed by the local network and ISP. The resolver itself sees the domain and client IP but never the URL path or credentials. DNS over HTTPS and DNS over TLS encrypt the query between device and chosen resolver, shifting trust to that resolver while the ISP sees only the connection to the resolver service.

ISP observes metadata but not HTTPS content

Once the IP address is known, the browser performs a TLS handshake followed by the encrypted HTTP request. The provider normally sees client and destination IPs, port 443, traffic volume, duration, unencrypted DNS queries and the Server Name Indication (SNI) unless Encrypted Client Hello (ECH) is used. Even with ECH the destination IP, volume and timing remain visible. One IP address frequently hosts many domains behind a CDN, so IP alone does not reliably identify the site.

Destination site receives the richest set of signals

The site (or its CDN) decrypts the traffic and obtains the client IP, full URL path and parameters, HTTP headers including Referer (subject to Referrer-Policy), cookies, authorization data, User-Agent information and any values collected by page scripts. Account login creates a stable identifier that survives IP changes. Browser fingerprinting combines language, timezone, screen dimensions and rendering behaviour to probabilistically link visits.

Third-party resources introduce additional observers

A single page often loads images, fonts, analytics scripts and widgets from multiple domains. Each third party receives its own request headers, cookies and identifiers. Removing cookies for one site therefore does not eliminate tracking performed by other origins.

VPN changes the route but adds a new observer

With a full-tunnel VPN the home ISP sees only the encrypted connection to the VPN server. The destination site sees the VPN exit IP. The VPN provider itself becomes the new observer that knows the user’s real IP and all destination addresses. HTTPS still protects content from the VPN, provided the user has not installed a trusted interception certificate.

A comparison of visibility with and without VPN:

• Site: home or mobile IP → VPN exit IP
• ISP: direct connections and sometimes DNS/SNI → connection to VPN and tunnel metadata
• VPN service: not involved → user IP, final destinations and DNS depending on configuration
• DNS resolver: domain and client IP → domain and VPN exit IP if DNS travels inside the tunnel
• Cookies and account: remain in the browser in both cases
• Browser fingerprint: largely preserved in both cases

Incognito mode clears local state, not network visibility

Incognito opens a temporary session whose cookies and storage are discarded when the window closes. Network observers, the destination site and any active VPN still see the same traffic metadata. Chrome documentation explicitly states that sites, the ISP and network administrators may continue to observe activity.

Effective privacy therefore requires first defining the precise information one wishes to hide and from whom, then selecting the appropriate combination of HTTPS, secure DNS, VPN routing, separate browser profiles and reduced third-party scripts.