Mistakes that make public Wi-Fi dangerous

Almost everyone loves the convenience of free Wi-Fi at airports, coffee shops, or shopping malls. With just a few simple steps, you can surf the web, work remotely, or chat with friends without worrying about mobile data costs.

However, behind that comfort lies many risks that not everyone realizes. Public Wi-Fi networks often lack the necessary security layers, becoming "fertile ground" for hackers to exploit. A little carelessness when connecting can put personal data, bank account information or even your entire device under the control of bad guys.

More worryingly, many seemingly harmless habits, such as trusting a familiar Wi-Fi network or letting the device automatically reconnect, are common "traps" that many people often fall into.

Here are six common mistakes that make using public Wi-Fi dangerous, and what you should avoid if you want to keep yourself safe.

1. Too much trust in previously connected Wi-Fi networks

One of the most common mistakes is to randomly connect to any open Wi-Fi network that appears, just because the name is familiar or seems “legitimate”. In fact, hackers can easily create a fake hotspot with a name like “Free_Café_WiFi” to fool users.

If you accidentally connect, you could be vulnerable to eavesdropping, data tracking, malware installation, or unencrypted traffic interception. This is especially dangerous if you’re logged into your bank, email, or social media accounts while you’re using it.

So before connecting, proactively ask staff at a public location to confirm the official network name, rather than trusting what is displayed on the screen. At the same time, do not ignore the “unsafe connection” warnings from the device. This simple vigilance will help you reduce the risk of becoming a target for hackers.

2. Let your device automatically connect to public Wi-Fi networks

One of the lesser-known risks of using public Wi-Fi is the auto-connect feature on phones and laptops. Normally, every time you connect to Wi-Fi at an airport, hotel or coffee shop, the device will save that network and automatically reconnect if it detects it is in range. This brings convenience, but also inadvertently opens the door for attackers.

The problem is that the device doesn’t actually verify that the network is legitimate. A hacker could create a hotspot with a name like “Hotel_WiFi” or “CoffeeShop_Free.” Your device could then automatically connect without prompting you, leaving you without even realizing you’ve been “trapped.” As a result, your traffic could be monitored, your data could be stolen, or you could be redirected to fake websites that steal your login credentials.

To avoid this, double-check your Wi-Fi settings. On iPhones and Androids, you can turn off auto-connect or choose to “forget” the network after you leave. On laptops, the option to manage saved networks is usually in the system settings. Auto-connect is useful at home, but when you’re in public, be proactive in choosing the network yourself to stay safe.

3. Keep file sharing always on

File sharing is a convenient feature, especially useful when you work from home or in a trusted office environment. It allows devices on the same network to easily exchange data, access documents, or print over the local network. However, this convenience can quickly become a serious security vulnerability if you forget to turn it off when using public Wi-Fi.

When file sharing is enabled, your device becomes “present” on the same network, meaning that strangers can detect the existence of your computer. Worse, depending on how it is configured, they can access shared folders, or exploit weaknesses to penetrate deeper into the system. Even if they don’t gain access, the mere fact that your device is visible makes you an easy target for automated scanning and attack tools.

On Windows, features like Network Discovery and File and Printer Sharing may be enabled by default if you previously marked a network as “private” and forgot to change it back. On macOS, the File Sharing section in Settings is also often overlooked, leaving users unaware that their computers are still sharing even when they switch networks.

To be safe, turn off sharing if you don't really need it. This is a small but effective step that will greatly reduce the risk of being tracked or accessed by a bad guy while you're simply surfing the web at a coffee shop.

4. Skip using a VPN

One of the simplest yet most effective ways to protect yourself on public Wi-Fi that is often overlooked by users is to use a virtual private network (VPN).

A VPN acts as an “encrypted tunnel” between your device and the internet, hiding all your online activities from the eyes of attackers. When you turn on a VPN, all your data, from the websites you visit, to your login information, to the messages you send, is encrypted, making it nearly impossible for hackers to decipher.

Conversely, without a VPN, any information transmitted over a public network is at risk of being exposed, especially when you visit websites that do not support the HTTPS security mechanism or use applications that lack encryption.

It’s worth noting that many people only think of VPNs when accessing online banking or “sensitive” services, while even seemingly harmless activities, like reading a newspaper or logging into social networks, can leave digital traces. Once a bad actor has a piece of information, it becomes much easier to exploit it further.

So, make it a habit to turn on your VPN whenever you connect to public Wi-Fi. Many quality VPN services have optimized their speeds so that you can barely feel the difference when surfing the web. This is an important layer of protection that you should not ignore.

5. Visit websites without checking HTTPS

In the past, HTTPS was only seen on banking or online shopping websites. But today, it has become a basic security standard that every user should pay attention to, especially when connecting to public Wi-Fi. A website without HTTPS means that the data you send, from passwords to personal information to search content, is at risk of being tracked by bad guys.

HTTPS works by encrypting the data transmitted between your browser and the server, preventing eavesdropping or interception. You can tell by the padlock icon in your address bar or by the URL starting with “https://” instead of “http://.” It sounds simple, but that little “s” is an incredibly important layer of protection.

In fact, many people often ignore this protocol check, thinking that every website is secure by default. However, there are still many small websites that only support HTTP, and some applications still secretly send data over unencrypted connections.

So get into the habit of checking the address bar before entering any sensitive information. If the lock is missing or your browser warns you that the connection is not secure, it's best to leave immediately to protect your personal data.

6. Logging into sensitive accounts without an extra layer of security

Public Wi-Fi is a huge convenience, allowing you to easily access the Internet anywhere from airports to coffee shops to hotels. However, it is not the ideal place to log into important accounts like online banking, work email or any service that contains sensitive information, unless you have taken extra security measures.

When you log in to an unsecured network, you are opening yourself up to attackers who can steal your data. Although most websites now use HTTPS to encrypt your connection, there is still a risk from sophisticated attacks, typically “man-in-the-middle attacks,” where hackers silently insert themselves between you and the website, collecting login information or session cookies to use as a tool to gain access.

This doesn't mean you can't check your bank balance or reply to work emails in public. It's about how you protect yourself. Simple steps like enabling two-factor authentication, using a password manager to autofill secure information, or connecting via a VPN can significantly reduce your risk.

In fact, public Wi-Fi is not necessarily the “enemy”. It is subjectivity and lack of vigilance that make you an easy target. A few small security measures can make a big difference in protecting personal data./.