Although the advent of Google Chrome has dented its popularity in recent times, Mozilla Firefox remains a key part of the online world. Every day, around 500 million people use the browser on their laptops, tablets, and phones, and there are plenty of good reasons for this.

The browser’s open source design and inspiring history as part of the Free Software movement are part of the appeal. But it’s also simply a very user-friendly, flexible product. Mozilla’s browser is also a safe option to go for if you want to stay anonymous and keep your private data secure.

Or so the conventional wisdom suggests – but you shouldn’t take any browser at face value. So we’ve put Firefox to the test and dug deeper to find out whether this is the best and safest browser around.

What are “secure browsers” and why are they important?

Before we assess the merits of Mozilla’s offering, it’s worth outlining exactly what makes a browser secure, and why that matters. Secure browsers won’t leak your browsing history to external observers or other local users. They will let you know about potential threats, link up with ways to neutralize them and hook up with encryption tools like VPNs without any problems.

This matters for a whole host of reasons. For one thing, web browsing without security is a great way to contract malware infections and leak private data to thieves. Browsing without security puts you at risk of surveillance, whether it’s by corporations or governments. And it also makes it easy for websites to track your movements via cookies and other devices – collecting data for their own private profit.

Introducing Mozilla Firefox

Mozilla is a free software collective that has been active since 1998. Originating as an offshoot from Netscape (which at that stage was starting to commercialize its operations), Mozilla had the idea of creating an open source, free web browser – as well as add-ons like mail clients.

It took a while, but in 2004 Firefox was ready for release. It immediately scored well with web users, who were frustrated with the “quality” if Microsoft Internet Explorer. By 2009, a massive 32% of web users were using Mozilla’s browser, although that percentage has more than halved since Google Chrome arrived.

Nowadays, Firefox is a slick product, with a committed customer base, versions for Linux, Windows, MacOS, and smartphones, as well as plenty of add-ons. Most importantly, it’s still free, and you can download it here.

Mozilla Firefox: key features

When you download the browser, here are a few basic features that make it stand out:

  • A clean interface with everything you’d expect from an elite browser.
  • Add-ons ranging from password managers and adblockers, to weather forecasters and maps.
  • Plenty of graphical themes to customize the look of your installation.
  • Synchronized accounts, so your bookmarks and passwords can follow you wherever you go.
  • Private browsing that leaves no trace of your activity, at least locally.
  • Instantly send tabs or bookmarks between devices, making it easy to share valuable links.
  • Memory management tools which generally make it more efficient than Chrome.
  • Easy integration with the Thunderbird email client.

How to use Mozilla Firefox Browser

Mozilla’s web browser will be familiar to almost any internet user. There’s nothing confusing on the front end. It just features the location bar, top menu, quick bookmark buttons, and the viewing window.

You can access the main options menu via a single click in the top right-hand corner. This menu opens up your “library” – which includes stored tabs, bookmarks, and any history you wish to store. You can call up the “content blocking” page to keep out cookies and trackers. And you can zoom straight into the add-ons section to add or remove apps.

Mozilla Firefox for Android

Mozilla for androidMozilla has released its browser for both iOS and Android phones, but it has a far lower market share than the desktop version. That’s a shame because the Android version is easy to install and totally functional.

The syncing options are very useful, making it easy to beam over bookmarks when required. And the privacy protections are at least as effective as Chrome. You can block tracking cookies and ads, and the history erasure is watertight, too. So even if your phone is stolen, thieves won’t have access to your browsing history.

The Android version also features browser extensions, which is welcome. So you can add emojis and themes to suit your personal style. However, the Android version does lack VPN support, which is a major drawback.

Mozilla Firefox for Mac

Mozilla for MacAnything from Mac OS 10.9 upwards can run Mozilla Firefox without any problems, and the browser is almost exactly the same as the Windows edition. You’ll need 512MB RAM, and 200MB of disk space to get up and running, but installation is simple.

Head to the download page, and press “download.” The site automatically detects that you’re using a Mac. When that’s done, a finder window will appear. Just drag the Mozilla icon to your apps tray, and you’re all set.

How to update Mozilla Firefox

Updating your browser to the latest version is always advisable, and in the case of Firefox, doing so isn’t complex. In fact, most of the time the browser will auto-update, saving you the effort.

Updates appear every few months. For instance, version 63.0 appeared in October 2018, while 64.0 landed in December 2018. So you can expect a short update process periodically. Check here for a full update list to get an idea of how it works.

By and large, updates aren’t too large, and they won’t take your browser offline for more than 10 minutes.

Is Mozilla Firefox safe?

Mozilla claims to offer the most secure private browser around. If you use private mode, the browser won’t store any history, cookies will be erased every session, and passwords won’t be retained either.

Firefox has made giant strides in other ways to become more secure. Mozilla has tweaked the notifications for possible attack sites, become better at integrating with popular antivirus packages, added private browsing mode, and also included a “Do Not Track” option to head off tracking cookies.

So generally speaking, Mozilla is pretty reliable when it comes to security and privacy. And the open source nature of their product means that bugs and nasty surprises aren’t likely to survive for long.

However, the company does extract “telemetry” data from browsers for analysis, and this includes quite a lot of information. Data sent includes “hardware, performance, usage, and customizations” – so pretty much everything you do with the browser. Fortunately, it can be turned off via the “privacy and security” menu.

The Privacy Policy provides some reassurance. For example, it states that personal data is routinely destroyed. But it also reports that “your information might end up on…computers in another country [which] may have a different level of data protection regulation than yours.”

That’s a little bit concerning and vague. And it makes using a VPN advisable to ensure total privacy.

Most common Mozilla Firefox issues

No browser is perfect, and Mozilla’s offering sometimes crashes at inconvenient times. Here are some common alerts that users will eventually come across.

  1. Firefox not responding – when the browser “hangs” permanently and won’t resume. This tends to be caused by faulty add-ons.
  2. Firefox critical error – this red screen of death would be the most alarming notification Mozilla provide – if it was real. Users sometimes receive these alerts, which tend to ask them to contact a “help desk”. They are almost always scams.
  3. SEC_ERROR_UNKNOWN_ISSUER alerts – if your browser returns this error message, then it’s a sign that Mozilla is working. This happens when Mozilla fails to authenticate a website’s certificate – an indicator that it could be unsafe.
  4. Your connection is not secure – an increasingly common error message, this tells you that Mozilla has detected an improperly configured site. You’ll have the chance to proceed, but it’s nice to have the option of staying clear.

Mozilla Firefox vs Google Chrome

Mozilla vs ChromeMozilla’s primary competitor these days isn’t Microsoft of Netscape – it’s Google. Let’s see how the two browsers compare:

Mozilla Firefox

Owning company: The Mozilla Foundation

Launched in: 2004

Security features:

  • Private browsing
  • Open source code reviews via the “bug bounty system”
  • Adblocking
  • Eliminate cookies
  • VPN add-ons
  • Security alerts

Private browsing available: Yes

Custom extensions available: Yes

Supported Platforms:

  • Windows
  • MacOS
  • iOS
  • Android
  • Linux

OpenSource: Yes

CloudSync: No


Google Chrome

Owning company: Alphabet

Launched in: 2008

Security features:

  • Anti-malware and anti-phishing alerts
  • 6-weekly patches
  • Sandboxing
  • Incognito mode (private mode)

Private browsing available: Yes

Custom extensions available: Yes

Supported Platforms:

  • Windows
  • Linux
  • MacOS
  • Android
  • iOS

OpenSource: No

CloudSync: Yes