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How to
How to check if WiFi is safe
You can’t prove a network is safe, but you can look for the warning signs that matter. Here is what to check, by hand or with an app.
Check six things: the exact network name, whether it uses a password (WPA2/WPA3), the sign-in page address, whether DNS answers match a trusted resolver, whether certificates are valid, and whether traffic goes through a proxy. The first three you can do by hand in a minute; SentryFi checks all six and gives a 0–100 risk score in about 45 seconds.
Checks you can do by hand
- Network name. Ask staff or look for a sign. Lookalikes add “Free”, swap letters or drop punctuation.
- Encryption. A lock icon or a password prompt means WPA2/WPA3 on the WiFi link. No password means you rely on each app’s own encryption (FTC).
- Sign-in page. Read the address bar. It should belong to the venue or its WiFi provider and ask only for terms, an ad, a room number or a loyalty login.
- Your apps’ warnings. A certificate or “not private” warning on a site you use every day is a red flag on this network.
Checks that need a tool
| DNS answers | Do address lookups on this network return the same answers as a trusted DNS resolver? Different answers can mean redirection. |
|---|---|
| DNS interception | Does the network answer lookups meant for an outside DNS server itself? Common in hotels; worth knowing. |
| Certificates | Do well-known sites present valid certificates, or is something in the middle? |
| Proxy | Is traffic passing through a middle server you didn’t set up? |
SentryFi runs these checks, explains each result in plain words and gives a 0–100 risk score. The WiFi check and score are free. It reports warning signs; it can’t promise a network is safe, and it is not a VPN.
What to do with the result
| Looks normal | Use it as usual over HTTPS. Still keep banking for networks you trust. |
|---|---|
| Some warnings | Browse only. Use mobile data or a VPN for logins. |
| Serious warnings | Disconnect, forget the network, tell staff if it claims to be theirs. |
Frequently asked questions
How do I know if a WiFi network is fake?
You can’t tell from the name alone. Confirm the exact name with the venue, look at the sign-in page address, and check for unusual DNS answers or certificate problems. A network asking for card details for free access is a strong sign.
Is a WiFi with a password always safe?
No. A password encrypts the link between you and the router, but everyone who knows the password shares the network, and the router can still redirect lookups. It is safer than open WiFi, not a guarantee.
Can I check WiFi safety on iPhone?
Yes. iPhone shows “Weak Security” for networks with old or no encryption in Settings > Wi-Fi. For DNS, certificates and proxies, use an app such as SentryFi, available on iPhone and Android.
