Cafe, airport and hotel Wi-Fi are shared networks run by someone you do not know. The risk is smaller than it was a decade ago, because most sites now encrypt traffic, but there are still a few things worth doing.
What others on the network can see
On a modern HTTPS site, other people on the Wi-Fi cannot read your messages, passwords or page contents. They can usually see that your device connected and which site names it looked up, and the network owner can see the same. On an old HTTP site, content can be read or altered. The website safety checker shows whether a site uses HTTPS.
The real risks
- Fake networks. An attacker can set up "Airport_Free_WiFi" to lure you. Connecting to the wrong network puts that person between you and the internet.
- Login portals that ask for too much. A real captive portal asks for a room number or an email, not your banking details.
- Certificate warnings. A warning page can mean someone is tampering with your connection.
- Shared devices. Other devices on the same network may probe yours if sharing is on.
Habits that protect you
- Confirm the network name with staff before joining.
- Never click through certificate warnings. Close the page and use mobile data instead.
- Use mobile data for banking and important accounts if you can. It avoids the question altogether.
- Turn off file sharing and AirDrop-style sharing from everyone while on public networks.
- Keep your device updated and use two-step verification so a stolen password is not enough.
- Turn off auto-connect to open networks and forget networks you no longer use.
Do you need a VPN?
A VPN encrypts traffic between your device and the VPN server, so the Wi-Fi owner and others on it cannot see which sites you visit. It helps on networks you do not trust and with older unencrypted sites. It does not protect you from phishing, malware or giving your password to a fake site, and it moves trust to the VPN company, which can see your traffic instead. Pick a reputable paid provider and test it with the VPN check. See free VPN risks and VPN, proxy or Tor for the comparison.
Home Wi-Fi counts too
Change your router's default admin password, use WPA2 or WPA3 and keep the router updated. The security checkup includes these.