Hotel captive portals: how the Wi-Fi login page became an ad channel and a security risk

In an article published in June 2026, The Next Web describes how hotel guest Wi-Fi login pages, known as captive portals, went from a simple technical access gateway to a hidden channel for data collection and advertising.

How a captive portal works

Anyone who has checked into a hotel with free Wi-Fi knows the drill: your laptop joins the hotel network, and instead of the regular internet, the browser automatically opens a login page. There, you enter your room number and last name and accept the terms of use. Only then does the device get full network access. Hotels, airports, cafés, and office business centers have used this technology, the captive portal, for decades to control guest network access and separate access tiers.

Why it became an ad channel and a security risk

A captive portal holds a privileged position in network traffic: before a device gets full internet access, all of its traffic passes through the login page. That makes the page a convenient spot to embed trackers, serve ads, and collect data about the device, browser, and location. Guests often get no clear notice of how much is collected or who receives the data next. Attackers actively exploit the same privileged network position. Fake access points that mimic a hotel's captive portal (an evil twin attack) let them intercept logins, passwords, and bank card details before the victim notices the network has been swapped.

Who profits from hotel guest Wi-Fi

Many hotels don't build their guest Wi-Fi infrastructure themselves. Instead, they outsource it to specialized network providers that serve hundreds of properties at once. These providers often monetize the login page itself through ads, affiliate offers, sponsored banners from travel agencies and taxi services, or by passing anonymized data to ad networks. The result: nominally free internet access becomes an extra revenue stream for both the hotel and its contractor.

An open café hotspot with no login at least doesn't create an illusion of control: guests understand they're joining a shared network alongside other visitors. A captive portal does the opposite. It creates an appearance of legitimacy and security. Guests read a request for personal details like a room number and last name as a hotel formality, not as data collection by a third-party network provider, and that lowers the guard of even cautious users.

The same logic applies at airports and business centers. The more official the login page looks, with the venue's logo, legal terms-of-use text, and corporate colors, the less reason users have to doubt that the venue's management is behind it rather than a third-party contractor with its own commercial interests.

What it means

Guests connecting to free hotel Wi-Fi rarely consider that the login page may simultaneously be a data collection point for ad networks and a potential entry point for an attack. Treat a captive portal with the same caution as any other unfamiliar public network, especially when handling sensitive data or corporate email.