A firewall is a staple part of any computer security setup, locking down network access to keep out any malicious programs. It’s such a staple that Microsoft even includes a firewall as part of Windows 10, meaning every Windows user has basic firewall protection.
Still, security-conscious users might want something a bit sturdier than the Windows freebie, and there are plenty of third-party firewall options out there too - most of which come bundled within larger security suites - like our top pick, Bitdefender - so you can get the full protection of anti-virus software too.
In case you’re unsure, a firewall is a layer of security that monitors network traffic, and usually sits between your private or home network and the wider internet. It keeps an eye on which programs or apps are sending signals in or out, and either flags or blocks any signals that are suspicious or malicious.
Most firewalls are host-based, protecting a single device or computer, but as the internet of things grows and we fill our homes with smart appliances there are more and more options for firewalls that protect your whole home network.
Best firewall reviews
1. Bitdefender Total Security 2018
We tend to recommend the Total Security package, which covers up to five devices simultaneously (across Windows, macOS, iOS, and Android) and includes webcam privacy protection, multi-layer ransomware protection, and the ability to manage your computer's security from a mobile device.
On top of that you get a password manager, parental advice tools, and even a VPN - though it's limited to 200MB per device, per day.
Prices start from £49.99/$69.99 for Internet Security, and £69.99/$89.99 for Total Security, but there's a 30-day free trial if you don't want to commit to paying the full price. Even better, right now UK users can save £20 off Internet Security or £30 off Total Security.
Read our Bitdefender Total Security 2018 review.
2. Norton Security Deluxe 2018
Norton Security is available in four tiers, and there's a firewall included in all of them from Standard up to Premium - you've just got to avoid the Basic version if you want to make sure you get the protection of a firewall.
Beyond the firewall and the core antivirus you get browser protection included, as well as a password manager, Scam Insight and performance tools to help speed up your computer.
Norton even offers a 100% virus-free guarantee or your money back, so you're covered even if it all goes wrong and some malware slips through the cracks.
The price of this protection weighs in at £69.99/$97.95 for 5 devices if you opt for the Deluxe version, though you can save money by opting for Standard (which only covers 1 device), and you can usually find discounts available throughout the year anyway.
Read our Norton Security Deluxe 2018 review.
3. ESET Internet Security 11
ESET 11 has a deceptively simple interface, which hides just how powerful the underlying tools are.
In addition to a standard firewall and antivirus, ESET can detect potentially unwanted applications trying to install themselves, and includes a secure browser for making payments or banking online.
You also get the Connected Home Monitor, which scans your local network by simulating an attack, giving you an overview of every device connected to your network, and highlighting any vulnerabilities. It'll also let you know whenever a new device connects so you can spot any neighbours trying to leech your Wi-Fi.
You get the firewall features with any of the Internet Security, Multi-Device, or Smart Security packages, with prices starting from £39.99/$59.99.
Read our ESET Internet Security 11 review.
4. AVG Ultimate 2018
While all of the security suites here include a firewall, AVG is one of the few to innovate on the tech, allowing you to see all of your connections in real-time. That might be a bit alarming at first - turns out your computer is making an awful lot of connections at any given time - but it's a great diagnostics tool.
Beyond the main firewall, AVG also features a file shield that scans files every time they're opened, a behaviour shield that watches for programs acting suspiciously, a web shield that scans all files downloaded from the internet and blocks known web attacks, and an email shield that protects you from unsafe attachments.
All that, and you get unlimited installs, making this a great choice for big families or anyone with lots of devices they want to keep protected.
Read our AVG Ultimate 2018 review.
5. Kaspersky Security Cloud
At first sight, there's little to choose between Kaspersky Security Cloud and Kaspersky Total Security. All the main antivirus tools required, including a firewall, are in both products. So, what's different about Security Cloud?
The main difference is that it contains adaptive security technology, which automatically adjusts your security settings and advises you based on your current activities.
That means things like monitoring which devices connect to your network, letting you know when you visit sites without security certificates, monitoring your password habits, and more, all in an unobtrusive way.
You can get Kaspersky Security Cloud for a year and use it across three devices for £34.99/$89.99 at time of writing. The family option offers 20 accounts, and is £69.99/$149.99 per year.
Read our Kaspersky Security Cloud review.