Many Windows PC users seek alternative firewalls to Microsoft Defender. For starters, third-party firewalls offer advanced features and more granular control over network traffic, enhancing intrusion detection. For those who prefer multi-layered security, these options present a valuable non-Microsoft choice. We’ve listed some of the best free firewall software for Windows.
Table of Contents
1. ZoneAlarm
The ZoneAlarm Free Firewall by Check Point software easily replaces Microsoft Defender firewall in the Windows Security app. Like Defender, it identifies potentially suspicious traffic and hides any open ports that hackers could exploit to break into a PC. It also disables malicious applications, and protects your computer on public Wi-Fi networks. The best part is a feature called “DefenseNet,” providing real-time security updates as emerging threats arise.
On top of this, ZoneAlarm provides a finer layer of perimeter protection for individual Wi-Fi networks. For comparison, Microsoft Defender offers “private” (which can be too easy) or “public” (which can be too strict), and “domain” level protection (which is rarely used). These settings can result in your Wi-Fi network being either too permissive or overly restrictive, blocking useful applications.
Instead of forcing you to above choices, ZoneAlarm firewall allows more granular tweaks. At the first level, it categorizes networks as either “trusted” or “public.” At the next, you can adjust the firewall zone rules with a slider as “off,” “medium,” or “high,” based on the Wi-Fi protocol used and security type.
The Defender firewall lacks a kill switch that can deactivate the Internet in response to intrusion events. In contrast, ZoneAlarm firewall offers two levels of Internet blocking: a “yellow lock” which ensures the Internet lock engages immediately. There is a more serious “red lock” which stops all Internet activity when your device is displaying numerous alerts. On the other hand, a “game mode” allows for more relaxed settings so you don’t encounter unnecessary alerts.
With a user-friendly interface, and early boot protection, ZoneAlarm gives you more compelling reasons to look for Microsoft firewall alternatives. It has its own antivirus subscriptions, but the free firewall tier blends quite well with other Windows Security features such as Microsoft Defender Antivirus.
2. GlassWire
GlassWire is another good free firewall you can use with your Windows PC. Its user interface is simple, slick-looking, and well organized, providing information on all the programs that receive and send data over your network and how much, so it’s easy for you to identify unusual activity. Like Microsoft Defender, you get event-by-event alerts through the Log Analysis feature. The GlassWire Protect feature keeps a tab on all your active apps including browsers, games, open applications, and host processes.
One feature I like about GlassWire’s free version is its neat and well-organized traffic monitoring. The live graphs provide details of past and present network activity, along with a color-coded anomaly detection feature that quickly helps you identify potential threats. Each application or program has a “GlassWire score (GW Score)” resembling a percentage, letting you know the relative safety of unknown applications.
You’ll get warnings of any network-related changes to your computer or suspicious changes to your apps or when a new app or service wants Internet access. Unlike the Defender firewall, which categorizes most malicious activities simply as unknown threats, GlassWire provides more detailed insights. For instance, it alerts you to any network-related changes on your device, ARP spoofing attempts, and DNS changes (one of the most common ways for hackers to penetrate a system).
The firewall also detects malware and blocks connections for misbehaving apps and bandwidth hogs on your computer. The free version of GlassWire already compares quite well to Microsoft Defender’s built-in firewall. As a replacement for Windows Defender Firewall, GlassWire integrates seamlessly with other Windows Security features.
Related: learn what firewalls do and why are they so important.
3. TinyWall
TinyWall is a little app (2 MB) that doesn’t need any expert knowledge to use and basically helps to improve on Windows’ firewall features. After installing it, TinyWall only allows the web traffic you permit through whitelisting. Its main advantage is its simplicity and the fact that it is completely free to use. A Detect feature keeps tab on your live applications and assigns different firewall rules such as normal protection, blocking, allowing outgoing, or autolearn.
While the software may seem minimalistic, it proves highly useful for real-time firewall implementation from the Windows system tray. You can whitelist by “process,” which displays all running processes. For example, if you’re using the Chrome browser, it automatically permits the application to operate freely on the network.
In addition, you can whitelist by “window,” allowing you to quickly unblock the network for the application you’re currently working on. The process of whitelisting is intuitive but requires some adjustment, as you’ll need to apply these firewall rules for every application you run on Windows. As the application is super lightweight, it doesn’t consume much PC resources unlike the Defender firewall which you can safely disable.
Unlike other free firewalls, TinyWall doesn’t bog you down with popup notifications and prompts every other time. Instead, its whitelisting features work through hotkeys or lists to ensure your apps can connect to the Internet without difficulties. You can also choose files, processes or services manually and give them temporary (a few hours) or permanent firewall permissions. You can also terminate any processes that are no longer useful.
Also read: find out the differences between a VPN and a firewall.
4. PeerBlock
When it comes to lightweight firewall alternatives to Microsoft Defender, PeerBlock stands out. Completely open-source and free, the software operates at a fundamental level, blocking specific IP addresses and entire IP address ranges. This feature is highly popular with network administrators, as it allows them to focus on precise IP addresses and ban them based on predefined rules.
You don’t need to be a technical expert to use this free firewall software. During installation, you can easily set it to block P2P, adware, and spyware, putting a significant portion of bad actors out of commission. Additionally, you can benefit from its predefined lists that are updated in real time. Despite its old and minimalist interface, the blocking action is highly effective, as you’ll see intrusion attempts being stopped while the application runs discreetly on your Windows desktop.
If you find that your normal web browsing is being disrupted, such as images not being visible on a webpage, there are solutions. You can use a handy feature called Always allow HTTP which lets you view those images, even if they have been added to your blocklist. As you continue to add your own IP addresses to the existing range, PeerBlock as a firewall system keeps growing.
In this guide, we saw a list of the best free firewall software alternatives to Windows Defender. As these are absolutely free, you might consider working with them rightaway as a replacement. However, there are some reputed firewall products available as a free trial, which come with more robust features.
For instance, any of Norton 360’s subscription plans come with a smart firewall and intrusion prevention system. I had worked extensively with Norton’s firewall products before and they provide one of the best protections against script-based attacks. Its 14-day trial gives you a glimpse into some of the newest firewall technologies. Avast also offers an endpoint firewall with a free 30-day trial.
Along with Windows, check out some of the best firewall apps for Android devices.
Image by DALL-E 3. All screenshots by Sayak Boral.
