Use mobile data, not public WiFi, for anything sensitive when you travel. Banking, payments and passwords belong on your 4G or 5G connection, which is encrypted between your phone and the mobile network and shared with nobody. Public WiFi in a hotel, airport or café is fine for browsing, because most websites and apps now use encryption (HTTPS), but it is shared with everyone nearby and easy to fake. The real risks are fake hotspots, login pages that collect your details and devices that are open to others. Staying on mobile data also takes less data than most travellers think: a full day of maps, messages and a couple of rides usually stays under 100 MB. This guide covers the risks, when public WiFi is fine, how to use it safely and how Belgian travellers can stay on mobile data abroad without expensive roaming.
Why mobile data is safer than public WiFi
Mobile data is safer for three reasons:
It is encrypted by default. Traffic between your phone and the mobile network is encrypted, and your SIM or eSIM identifies your phone to that network.
It is not shared. On public WiFi, everyone in the same café is on the same network as you. On mobile data, nobody nearby can see your device.
It is hard to fake. 4G and 5G check that the network is genuine, and a fake mobile network takes specialised equipment and is illegal, while a fake WiFi hotspot takes a laptop and a few minutes.
Mobile data does not stop phishing, though. A fake message or website can reach you on any connection, so keep your phone updated and stay alert.
What are the real risks of public WiFi?
Fake hotspots
The biggest risk is a network that is not what it claims to be. Anyone can create a hotspot called "Airport Free WiFi" or copy the name of your hotel network, and everything you do on it then passes through their device. The Centre for Cybersecurity Belgium warns about exactly this on Safeonweb.
Login pages that ask for too much
A genuine WiFi login page asks for a room number or a click to accept the terms. A page that asks for your social media password, or for bank card details on a network that should be free, is a red flag.
Open networks without a password
On an open network without a password, the connection between your phone and the router is often not encrypted. HTTPS still protects most websites, but older sites and some apps do not use it.
Your device is visible to others
File sharing, AirDrop open to everyone and automatic connection to open networks all make your phone easier to reach for strangers on the same network.
When is public WiFi fine to use?
Browse on public WiFi, bank on mobile data. According to the US Federal Trade Commission, connecting through public WiFi is usually safe today because most websites use encryption, and Google reports that 99% of pages opened in Chrome on Android load over HTTPS. What matters is what you do on it:
Fine on public WiFi | Better on mobile data |
|---|---|
Reading the news | Online banking |
Downloading offline maps | Payments and bank card details |
Streaming on a password protected hotel network | Entering passwords |
Browsing sites with a lock icon | Logging in to your email or work accounts |
How to use public WiFi safely while travelling
Ask staff for the exact network name before you connect, and pick the network that needs a password.
Check for the lock icon or "https" in the address bar before you type anything.
Never enter bank card details on the login page of a free WiFi network.
Use a VPN. A VPN (virtual private network) creates an encrypted tunnel between your device and the internet, so the WiFi network cannot see what you do. Choose a trusted provider, because some free VPNs make money from your data.
Turn off automatic connection to open networks and file sharing, and forget the network when you leave.
Keep your phone updated and turn on two step verification for important accounts.
Use your phone as a hotspot instead
Turn on the personal hotspot on your phone when your laptop needs to go online at the airport. Your laptop then uses your mobile data through a private, password protected network that only you control. A laptop uses more data than a phone, so keep an eye on your data balance.
How much mobile data do you need to avoid public WiFi?
Very little. Light travel use costs far less data than most people expect, as long as you avoid video:
What you do | Typical data use |
|---|---|
3 to 5 MB per hour, 7 to 10 MB with live traffic | |
Under 1 KB | |
WhatsApp photo | 100 to 500 KB |
WhatsApp voice call | 0.3 to 0.5 MB per minute |
Boarding pass or train ticket | Under 1 MB to download, nothing once saved |
Taxi or ride app booking | A few MB per ride |
Bank app approval | A fraction of 1 MB |
WhatsApp video call in HD | Up to 480 MB per hour |
For light use, around 1 GB covers a week. You do not need a big bundle to stay off public WiFi, only a connection that works when you land.
How to stay on mobile data abroad without roaming costs
Inside the EU, use your Belgian plan as usual. The roam like at home rules, extended until 2032, let you use it at no extra charge, within fair use limits, and they also apply in Norway, Iceland, Liechtenstein, Moldova and Ukraine. Outside the EU, in countries such as Morocco or Albania, roaming can be expensive, which is why so many travellers fall back on public WiFi exactly where they are most exposed. For light data use, these are the cheaper alternatives:
A travel eSIM. An eSIM is a digital SIM card that you install before you leave, so your phone connects to a local mobile network as soon as you land. Your Belgian SIM can stay active next to it. Check first that your phone is on the list of eSIM supported phones.
A local SIM card. Cheap in many countries, but you have to find a shop after landing and swap SIM cards.
Offline downloads on a trusted network. Save maps, tickets and playlists on your hotel WiFi before you head out, so you need even less data during the day.
Stay on mobile data with Firsty
Stay on mobile data wherever you land. With a travel eSIM from Firsty, there is no hotspot to hunt for, no SIM card to swap at the airport and no roaming setting to remember, and your own number stays reachable. Every connection Firsty sells also connects someone in Belgium who needs one, not as charity, but as how the business works. Things are moving, so keep an eye on what Firsty is building and discover more at Firsty.app.
FAQ
Is public WiFi safe?
Public WiFi is usually safe for everyday browsing, because most websites and apps use encryption (HTTPS). The main risks are fake hotspots with a trustworthy name, login pages that ask for personal or payment details, and open networks without a password. Use mobile data for online banking and payments.
Is mobile data safer than WiFi?
Yes, mobile data is safer than public WiFi. Your 4G or 5G connection is encrypted between your phone and the mobile network, it is not shared with strangers and it is much harder to fake than a WiFi hotspot. Your own password protected WiFi at home is also safe.
Can someone hack my phone through public WiFi?
It is unlikely if your phone is up to date, but public WiFi does make some attacks easier. A fake hotspot can show you phishing pages, and open file sharing can expose your device. Keep your software updated, turn off automatic connection to open networks and only use websites with a lock icon.
Is hotel WiFi safe?
Hotel WiFi is reasonably safe if it is password protected and you have confirmed the network name with reception. Every guest shares the same network, so use a VPN or your mobile data for banking and payments.
Is airport WiFi safe?
Airport WiFi is one of the most common places for fake hotspots, because many travellers look for free internet at the same time. Check the official network name on the airport website or signs, never enter card details on the login page of a free network and use mobile data for anything sensitive.
What is a VPN and do I need one on public WiFi?
A VPN, or virtual private network, creates an encrypted tunnel between your device and the internet, so the WiFi network cannot see what you do. It is a good extra layer on public WiFi. Choose a trusted provider, because some free VPNs make money by collecting user data.
What is a mobile hotspot?
A mobile hotspot, or personal hotspot, turns your phone into a small WiFi network that shares your mobile data with other devices, such as a laptop or tablet. It is protected by your own password, which makes it safer than public WiFi.
How much mobile data do I need when travelling?
Around 1 GB for a week of light use. Google Maps navigation uses about 3 to 5 MB per hour, a WhatsApp voice call 0.3 to 0.5 MB per minute, a taxi or ride app a few MB per ride, and a saved boarding pass no data at all. Video is the exception: an HD WhatsApp video call can use up to 480 MB per hour.
What are cheaper alternatives to roaming outside the EU?
A travel eSIM is the simplest alternative: you install it before you leave and your phone has mobile data as soon as you land. A local SIM card also works but means finding a shop and swapping cards. Downloading maps and tickets on a trusted WiFi network before you go out lowers how much data you need.
Is Proximus Public Wifi still available?
Proximus ended its Public Wifi option, which connected customers automatically to its secured public hotspots, on 1 December 2025, and now points customers to mobile data on its 4G and 5G network instead. Abroad, mobile data or a travel eSIM is usually the more reliable and safer alternative.
Does using mobile data in the EU cost extra?
No. Under the EU roam like at home rules, extended until 2032, you can use your Belgian mobile plan in other EU countries, as well as Norway, Iceland, Liechtenstein, Moldova and Ukraine, at no extra charge, within fair use limits. Outside the EU, roaming charges can be high, which is where a travel eSIM helps.
