Public Wi-Fi, charging and travelling with devices

Is public Wi-Fi safe? Free Wi-Fi at cafés, airports and hotels comes with risks, mostly from open networks and fake hotspots, and those risks are easy to reduce once you know how they work. The same goes for public charging points when a battery is running low. This guide explains how public networks and fake hotspots work, how to change the Wi-Fi settings that matter on common devices, what official guidance says about public charging, and how the Australian Signals Directorate’s Australian Cyber Security Centre (ASD’s ACSC) describes travelling with devices.

Why public Wi-Fi carries risk

On a home network, you control who can connect (the home Wi-Fi and router security guide explains those settings). On a public network, anyone nearby can. The ACSC’s public Wi-Fi page says hotspots “can be accessed by anyone, and are often free and unsecured”, which makes them “an attractive target for cybercriminals.”

Two things make the difference:

• Encryption between you and the website. Many websites and apps use HTTPS, which scrambles information between your device and the site. Even on an open network, others can’t easily read it. The ACSC describes looking for “‘https’ and the lock symbol in the address bar”.
• Whether the network itself is genuine. This is where fake hotspots come in.

How fake hotspots work

A Wi-Fi network’s name is just a label, and anyone can choose any label. The ACSC says: “Anyone can create a free Wi-Fi hotspot, including cybercriminals”, and “Wi-Fi and hotspot names are not unique, and they can be reused by anyone.”

A fictional example

Mia is waiting for a flight. Her phone shows two networks, “Airport Free WiFi” and “Airport_Free_WiFi”. One is real. The other was set up a few minutes ago by someone sitting nearby, with a sign-in page that asks for an email address and password “to get online”. Mia checks the airport sign, which lists the real name, and joins that one instead.

A fake network can also show pop-ups asking you to install something, or warning pages that look like a browser error. The ACSC says: “If your browser displays a warning message when you try to visit a website, do not continue.”

How to check a hotspot before connecting

The ACSC’s public Wi-Fi guidance and its Secure your mobile phone guide describe these habits:

1. Check the name on signs at the venue or with staff.
2. Turn off auto-join for public hotspots. The ACSC says: “Disable features such as ‘auto-join’ or ‘auto connect’ for public hotspots.”
3. Prefer password-protected networks over ones marked “open” or “unsecure”.
4. Choose “public” when a computer asks what kind of network it is. This turns off file sharing.
5. Forget the network afterwards, so the device doesn’t rejoin it later.
6. If in doubt, don’t connect. Use mobile data or a personal hotspot instead.

How to turn off Auto-Join or forget a network on iPhone and iPad

Based on Apple’s instructions (checked October 2026). Menus can change; Apple’s guide has the latest steps.

1. Open Settings and tap Wi-Fi.
2. Tap Edit, then tap the info button (i) next to the network.
3. To stop the phone joining it automatically, turn off Auto-Join.
4. To remove it completely, tap Forget This Network, then tap Forget to confirm.

On a Mac, Apple describes the same options under System Settings > Wi-Fi > Advanced: click the More Options button (…) next to the network, then turn off Auto-Join, or choose Remove From List and click Forget. Apple notes that if your devices use iCloud Keychain with the same Apple Account, forgetting a network on one device makes the others forget it too, and that a forgotten network can still appear in the list of available networks.

How to forget a network on Android

Based on Google’s instructions (checked October 2026). Menus vary between phone makers and Android versions; Google’s guide has the latest steps.

1. Open the Settings app.
2. Tap Network & internet, then Internet.
3. Touch and hold the saved network.
4. Tap Forget.

Google explains that with Wi-Fi on, a phone “automatically connects to nearby Wi-Fi networks you’ve connected to before”, which is why forgetting a public network stops it reconnecting. Google’s page doesn’t describe a separate auto-connect switch; some phone makers’ own help pages do.

How to set a Wi-Fi network to Public in Windows 11

Based on Microsoft’s instructions (checked October 2026). Microsoft’s guide has the latest steps.

1. Open Settings > Network & internet > Wi-Fi.
2. Select the Wi-Fi network you’re connected to.
3. Under Network profile type, choose Public network (Recommended).

Microsoft says that with a public profile, “Your PC will be hidden from other devices on the network”, and file and printer sharing won’t work. It says new networks are set to Public by default. Saved networks can be changed under Wi-Fi > Manage known networks.

Banking and other sensitive tasks

The ACSC suggests thinking twice before using services such as online banking on public Wi-Fi, and waiting for a trusted connection such as home, work or mobile data where possible. Its phone guide lists passwords, card details and banking information among things not to send over public Wi-Fi. Our guide to banking and shopping on your phone covers this in more detail.

What about a VPN?

A VPN (virtual private network) is an app or service that encrypts everything between your device and the VPN provider, so the local network can’t see it. The ACSC describes a VPN as “a service that encrypts and secures your data when using the internet”, and says people who use public Wi-Fi often may want a reputable one. It also points out that VPN providers can see a lot of user data, and describes researching a provider’s privacy practices and independent reviews before choosing.

Charging in public

A USB cable carries data as well as power. That’s why official guidance treats unknown cables and ports with caution. The ACSC’s Security tips for travelling says: “Never use someone else’s peripherals such as chargers, cables and other removable devices.” Its phone guide describes not plugging in a cord or USB device you find or are given.

Cyber Security NSW’s Safe remote working guide warns that “Public USB ports may be tampered with and can spread malware”, and describes using your own charger and cord in a wall power point instead.

Travelling with devices

The ACSC’s travel tips apply to trips interstate and overseas. Its travel checklist groups them into three stages.

Before the trip

• Back up data, and leave behind devices or information that aren’t needed. The ACSC says this “limits how much data is at risk” if a device is stolen. See how the 3-2-1 backup approach works.
• Turn on multi-factor authentication. The ACSC notes international roaming may be needed to receive text-message codes overseas.
• Protect each device with a PIN or passphrase, and keep software updated.

During the trip

• The ACSC describes devices being “set to automatically lock after a short time (less than 5 minutes)”, locked when unattended and kept with you rather than in the hotel room.
• It says to “Avoid using public devices such as computers in a hotel business centre.”
• It describes using trusted connections such as mobile data or a personal hotspot.
• It says to “Be careful of sharing your location and personal information on social media.”
• It suggests considering “turning off Wi-Fi, Bluetooth and near-field communication (NFC) on your devices when not in use.” NFC is the tap-to-pay radio.

After the trip

• Consider changing PINs and passwords for devices and accounts.
• Wipe any USB drives or memory cards used while away.

The ACSC’s travel guide also notes that “Some countries may force you to unlock your device if you use biometrics.” For destination-specific information, it points to smartraveller.gov.au/destinations.

Things to watch for

• Two networks with almost the same name. The ACSC’s guidance is to confirm the real name with the venue.
• A hotspot sign-in page asking for passwords or account details beyond what’s needed to get online. This works like other phishing tricks that collect logins.
• Browser security warnings on a public network. The ACSC describes stopping, disconnecting and forgetting the network.
• Unexpected prompts to install an app or “update” while on a hotspot.
• Signs a device may be compromised. The ACSC’s travel checklist lists apps crashing, unexpected pop-ups, unfamiliar account activity, unknown emails in the sent folder, and unusually high battery or data use.

Common questions

Is public Wi-Fi safe to use?

Public Wi-Fi carries risks, but they’re easy to reduce once you know how they work. The ACSC says hotspots “can be accessed by anyone, and are often free and unsecured”, and that anyone can create one, including cybercriminals. Its guidance describes checking the network’s real name with the venue, turning off auto-join and waiting for a trusted connection for tasks like banking. The full list is in how to check a hotspot before connecting.

Is public Wi-Fi safe if a website uses HTTPS?

HTTPS helps, but it isn’t the whole picture. It scrambles information between your device and the website, so others on an open network can’t easily read it. The ACSC still describes checking the network name and avoiding sensitive tasks on public Wi-Fi where possible, because a fake hotspot can show fake sign-in pages and warnings. See how fake hotspots work.

Do I need a VPN on public Wi-Fi?

The ACSC says people who use public Wi-Fi often may want a reputable VPN, which it describes as “a service that encrypts and secures your data when using the internet”. It also points out that VPN providers can see a lot of user data, and describes researching a provider’s privacy practices and independent reviews before choosing one. More in what about a VPN?

Is it safe to charge my phone at a public USB charging station?

Official guidance treats public USB ports with caution, because a USB cable carries data as well as power. The ACSC says: “Never use someone else’s peripherals such as chargers, cables and other removable devices.” Cyber Security NSW warns that public USB ports may be tampered with, and describes using your own charger and cord in a wall power point. See charging in public.

Can I do online banking on public Wi-Fi?

The ACSC suggests thinking twice before banking on public Wi-Fi, and waiting for a trusted connection such as home, work or mobile data where possible. Its phone guide lists passwords, card details and banking information among things not to send over public Wi-Fi. Its travel tips list a personal hotspot from your own phone as a trusted connection. See banking and other sensitive tasks.

What do I do if I think my device was compromised while travelling?

The ACSC’s travel checklist lists warning signs such as apps crashing, unexpected pop-ups, unfamiliar account activity, unknown emails in the sent folder, and unusually high battery or data use. Its Report and recover page explains where to get help, and its 24/7 hotline is 1300 CYBER1 (1300 292 371). Our guide to securing online accounts covers changing passwords and MFA.

Where to get official help

• ASD’s ACSC: public Wi-Fi guidance, and the 24/7 hotline on 1300 CYBER1 (1300 292 371), listed on the ACSC’s where to get help page.
• Smartraveller for official travel advice.
• If a phone goes missing on a trip, see what to do about a lost or stolen phone.
• The home Wi-Fi security checklist covers the network at home.