在国外用公共 Wi-Fi，怎样才不冒险
机场和咖啡馆的 Wi-Fi 很好用，前提是分清哪些事能在上面做、哪些不能。
快速解答
- Use public Wi-Fi for reading and downloading, but do banking over your own mobile data instead.
- Turn off auto-join for remembered networks: a phone can rejoin a same-named network that is not the real one.
| Task | Public Wi-Fi | Your own mobile data |
|---|---|---|
| What you see | What it may mean | What to do |
|---|---|---|
| Account group | What losing it costs you | Where to use it |
|---|---|---|
- 1
- 2
- 3
- 4
- 5
- 6
常见问题
Is it risky to join airport Wi-Fi briefly just to check a flight?+
Reading public information such as a flight status is low-risk use. What deserves care is not the reading but the join page, which may ask for more than it needs, and the chance that you drift into something else — opening a banking app because a notification happened to arrive. Checking a flight is fine. If you already have your own data, using it settles the question faster.
With an eSIM, do I need to touch public Wi-Fi at all?+
It still helps in some cases, particularly large downloads, bulk photo uploads and heavy app updates. Putting those on Wi-Fi preserves your allowance for time spent outside, which is when you actually need it. A good division is volume on Wi-Fi and privacy on your own data.
Is a password-protected network safer than an open one?+
It is better in that it keeps passers-by out, but a password given to every guest does not separate you from the other guests, and it says nothing about who runs the network. The safer habit is to divide tasks by consequence regardless of whether there is a password, keeping anything that touches an important account on your own data.
Do I need to buy a VPN before travelling?+
Not for everybody. It reduces what a network owner can see, but it does not address the main risk, which is you entering details into a page that is not genuine. If you prepare accounts at home, turn on two-step verification and keep sensitive work on your own data, you already have most of the benefit. You also need to check the destination's own rules on VPN use, which differ from place to place.
What if I already accepted a network's request to install a profile?+
Remove it from the device's settings, where that menu lives differs by manufacturer and OS version, then forget the network. Change the passwords of your important accounts from a network you trust, such as your own data or your home connection. If you are not sure what was installed, screenshot it and ask us before deleting.
Is it all right for a child to use public Wi-Fi?+
Yes, provided that device carries no accounts touching money or the family's main email, and automatic joining is turned off. Better than forbidding it is arranging that the child does not need somebody else's network: download content in advance, or share a hotspot from a parent's phone when needed, because children rarely notice what a pop-up page is asking for.
常见问题
With an eSIM, do I still need public Wi-Fi?+
It still helps, especially for large downloads and photo backup, keeping your plan's allowance for time outside.
Should I use a VPN on public Wi-Fi?+
It reduces what the network owner can see but does not remove every risk, and some countries regulate VPN use, so check local rules first.