Open Source Mozilla Firefox Alternatives

    The best open source alternative to Mozilla Firefox is Vivaldi, which is both free and Open Source. If that doesn't suit you, our users have ranked more than 100 alternatives to Mozilla Firefox and loads of them is open source so hopefully you can find a suitable replacement. Other interesting open source alternatives to Mozilla Firefox are Pale Moon (Free, Open Source), Brave (Free, Open Source), Waterfox (Free, Open Source) and Chromium (Free, Open Source).

    The list of alternatives was last updated Jun 6, 2021

    Platforms

    • Windows
    • Mac
    • Android
    • Linux
    • Android Tablet
    • iPhone
    • iPad
    • BSD
    • PortableApps.com
    • Kindle Fire
    • Windows Phone
    • Xfce
    • AmigaOS
    • Chrome OS
    • Haiku
    • KDE
    • Google Chrome
    • Arch Linux
    • Windows S
    • Blackberry

    Features

    • Tabbed browsing
    • Built-in Ad-blocker
    • Web Browsers Based on Chromium
    • Lightweight
    • Privacy focused
    • Extensible by Plugins/Extensions
    • Block ads
    • Portable
    • Web Browsers Based on Firefox
    • Built-in Download Manager
    • Customizable
    • Night mode/Dark Theme
    • Privacy protection
    • Built-in RSS reader
    • Mouse gestures
    • Based on Webkit engine
    • Cloud sync
    • Block trackers
    • Multiple languages
    • Security focused

    License

    × Clear
    • Free
    • Open Source
    • Paid
    All Filters

    • The Vivaldi browser protects you from trackers, blocks unwanted ads, and puts you in control with unique built-in features. View 131 alternatives to Vivaldi
      Most users think Vivaldi is a great alternative to Mozilla Firefox.
      • FreeOpen Source
      • Mac
      • Windows
      • Linux
      • Android
      • Android Tablet
      Vivaldi vs Mozilla Firefox
      pros, cons and recent comments
       all • positive • negative      relevance • date
      s20 A great browser with enough options to keep power users happy for days. Sadly based on Chromium, it is subject to the limitations of that platform, but it also gets their add-on store, so that's great too.
      Top positive comment  11 months ago

      4
      RemovedUser The side tab function is very efficient.
      Top positive comment  almost 2 years ago

      13
      It's very laggy to open some pages, on Linux, it's hard to install and often lacks basic codecs, so videos on youtube looks pixelated!
      Top negative comment  over 1 year ago

      10
      architsastam Vivaldi is simply the next stop for Firefox users, while it is freeware, it is technically closed and open-source. Some of the browser's components are closed while some are open and the source codes are available on Vivaldi's website.
      Positive comment about 2 months ago

      1
      josephcw Vivaldi is very fast and has unusual features. Unfortunately, it's not open-source, so I can't recommend it over Firefox.
      Positive comment 5 months ago

      0
      It is flexible, user-centric, contains features to improve productivity so much that you cant go back to any other browser at least on desktop!
      Positive comment 6 months ago

      0
      Firefox is open sourced Vivaldi is not
      Negative comment 8 months ago

      -2
      Show more comments
      7 of 31 comments
    • Pale Moon is an Open Source, Goanna-based web browser available for Microsoft Windows and Linux (with other operating systems in development), focusing on efficiency and customization. Make sure to get the most out of your browser!. View 176 alternatives to Pale Moon
      Almost everyone thinks Pale Moon is a great alternative to Mozilla Firefox.
      • FreeOpen Source
      • Mac
      • Windows
      • Linux
      • WinPenPack
      Pale Moon vs Mozilla Firefox
      pros, cons and recent comments
       all • positive • negative      relevance • date
      When Firefox become more and more bloated Pale Moon is lightweight, offers stability and compatibility with the FF extensions (for now, because WebExtensions). It also works great with a lot of tabs(400 or more).
      Top positive comment  over 4 years ago

      20
      So far, Pale Moon gives me features I want that Firefox has disabled and will soon be gone completely in Firefox 57. Firefox 57 will be a Chrome-like boat anchor. Pale Moon is very stable, lightweight and is fast
      Top positive comment  about 4 years ago

      11
      Old looking UI. It needs to be updated.
      Top negative comment  about 1 year ago

      2
      jakeBeefiller Privacy and security focus.
      Positive comment 3 months ago

      0
      Pale Moon is fast, secure and open source. It's compatible with old Firefox's extensions and is private. Lightweight and private. The best alternative
      Positive comment 10 months ago

      2
      It has the most similarity to firefox whitout being firefox nightly, which is just firefox but more updated and usually more unstable. It has a mid 2000's site like feel without feeling outdated. It has tons of features, and has some compatibility features with Gecko/Firefox add-ons, which in my opinion makes it a great alternative to firefox. It does not have a blacklist of sites, unlike firefox.
      Positive comment over 1 year ago

      -2
      Fast browser. Simple preferences setup. Clean install with no hidden junk in my registry or secret files like chrome and mozilla-firefox. My backup browser is Waterfox. i run on win7 x64.
      Positive comment almost 2 years ago

      4
      Show more comments
      7 of 18 comments


    • Brave Web Browser is a fast, free, secure web browser with a built-in ad blocker*, tracking and security protection, and optimized data and battery experience. View 191 alternatives to Brave
      Most users think Brave is a great alternative to Mozilla Firefox.
      • FreeOpen Source
      • Mac
      • Windows
      • Linux
      • Android
      • iPhone
      • Android Tablet
      • iPad
      • Electron / Atom Shell
      Brave vs Mozilla Firefox
      pros, cons and recent comments
       all • positive • negative      relevance • date
      Ola It's great with a browser that is trying to solve the issue with ads on the web AND the issue that publishers needs money to build cool sites.
      Top positive comment  8 months ago

      -1
      JohnFastman Currently (March 2017), Brave is not a mature project. It's an open-source privacy-oriented browser and very fast. But you rely on the developers to provide most of the privacy settings, and you can't install extensions. Firefox remains much more customizable via it's about:config menu options.
      Top positive comment  over 4 years ago

      5
      Not secure at all, based on Chromium as 99% of the browsers. It doesn't get my respect. No differencial, just Chromium + some extensions implemented.
      Top negative comment  over 1 year ago

      41
      Kedman The best of the best : no ads, very fast, very safe and very free and work with chrome extension
      Positive comment 24 days ago

      0
      enricoce it's faster, more secure, sync what you want through different platforms, safe.
      Positive comment 3 months ago

      -1
      Their privacy claims go as far as Facebook saying "we don't sell your data". You are tracked by cryptocurrency companies (Uphold & Brave rewards), they can ask for ID card as well. In the end this is just Chromium with a build-in ponzi scheme; slower and less private too.
      Negative comment 5 months ago

      1
      fast, bulit-in support for tor peer to peer sync, etc.
      Positive comment 7 months ago

      -1
      Show more comments
      7 of 15 comments
    • Waterfox is a high performance browser based on the Mozilla platform. Made specifically for 64-bit systems, Waterfox has one thing in mind: speed. View 107 alternatives to Waterfox
      Almost everyone thinks Waterfox is a great alternative to Mozilla Firefox.
      • FreeOpen Source
      • Mac
      • Windows
      • Linux
      • PortableApps.com
      Waterfox vs Mozilla Firefox
      pros, cons and recent comments
       all • positive • negative      relevance • date
      Akino Waterfox is made for x64 (amd64) CPUs, and it also delivers you a fine service concerning privacy, firstly devs removed telemetry and tracking implented recently in Firefox. Secondly it supports old extensions and pocket was removed
      Top positive comment  almost 4 years ago

      21
      JohnFastman It depends what you want from a Firefox alternative. Waterfox is essentially identical to Firefox, except that it's a 64-bit, not a 32-bit browser. It's still open source and fully compatible with all options, extensions and everything else.
      Top positive comment  over 4 years ago

      14
      Dated when compared to actual Firefox, some extensions doesn't work properly due to it being based on a old version of Firefox.
      Top negative comment  over 1 year ago

      5
      retroplayeryt It's like the Chromium, but for Firefox.
      Positive comment 4 months ago

      0
      Schnatt_App clean striped open-source alternative if you seek a browser without any telemetry features
      Positive comment over 1 year ago

      6
      Please keep it updated quicker vs Firefox. That is my only complaint.
      Positive comment over 1 year ago

      1
      khanhlong17112000 The 64 bit version of this browser is very lightweight. In fact, it can compare with 32 bit version of another browser.
      Positive comment over 1 year ago

      1
      Show more comments
      7 of 16 comments
    • Chromium is the open-source browser project from which Google Chrome takes its source. View 161 alternatives to Chromium
      Almost everyone thinks Chromium is a great alternative to Mozilla Firefox.
      • FreeOpen Source
      • Mac
      • Windows
      • Linux
      • BSD
      • PC-BSD
      • Xfce
      • Blink Rendering Engine
      Chromium vs Mozilla Firefox
      pros, cons and recent comments
      JohnFastman Chromium is the core of the Chrome browser. It functions well enough as a browser but lacks some of Chrome's features (e.g. built in language translator). Even though Chromium is open source, it still "phones home" to Google, which has privacy implications. There are more private Chromium-based browsers, such as Brave and Iridium.
      Top positive comment  over 4 years ago

      25
      SiliconeValley Chromium is most likely the heart of Google Chrome, Opera and some browsers without fancy features.
      Top positive comment  almost 5 years ago

      4
      Chromium doesn't have DRM features and some codecs implemented like Google Chrome, it's open-source but all your data goes to Google when you use Chrome Store to download apps since there is no Chromium store. Also, this browser is hard to install on Windows, you have to compile or download versions that are created by the users daily, so it means you do not have a proper installer like on Linux/BSD.
      Top negative comment  about 2 years ago

      16
      Different from Firefox, it doesn't autoupdate on Windows. You need to basically download a new browser per wiki and install... On Linux, it's more easy to manage updates depending on the distros, on Arch Linux/Debian it's so easy, but hard on Ubuntu/Mint.
      Negative comment 11 months ago

      4
      By default, it doesn't support DRM because the missing Widevine plugin/codec
      Negative comment about 1 year ago

      1
      Full Webbrowser, Source of Chrome, has html5 / css3 / js / addons / bookmarks / sync, etc. So, why not? It seems there was a Troll on this page...
      Positive comment almost 5 years ago

      0
      jacksarrocco Chromium is not a ready-for-the-consumer software. It is a open source project that needs to be implemented to make it work.
      Negative comment almost 5 years ago

      -78


    • Firefox Nightly is the development (alpha) release channel of Mozilla Firefox . View 159 alternatives to Firefox Nightly
      Most users think Firefox Nightly is a great alternative to Mozilla Firefox.
      • FreeOpen Source
      • Mac
      • Windows
      • Linux
      • Android
      • Chrome OS
      • Android Tablet
      • Kindle Fire
      Firefox Nightly vs Mozilla Firefox
      pros, cons and recent comments
      If you want a more updates and If you are tester, you liked her!
      Positive comment about 1 year ago

      3
    • Firefox Developer Edition brings you latest features, fast performance, and the development tools you need to build for the open web. View 178 alternatives to Firefox Developer Edition
      Almost everyone thinks Firefox Developer Edition is a great alternative to Mozilla Firefox.
      • FreeOpen Source
      • Mac
      • Windows
      • Linux
      • PortableApps.com
      Firefox Developer Edition vs Mozilla Firefox
      pros, cons and recent comments
      axy_david If you have issues with Firefox not being fast enough but don't wanna go Chrome try this! Also faster than Chrome.
      Positive comment over 3 years ago

      7
      sarpertoksoz offical edition of firefox
      Positive comment almost 3 years ago

      0
    • Falkon, formerly QupZilla, is a QtWebEngine based cross-platform web browser. It aims to be a lightweight web browser available through all major platforms. View 167 alternatives to Falkon
      Most users think Falkon is a great alternative to Mozilla Firefox.
      • FreeOpen Source
      • Windows
      • Linux
      Falkon vs Mozilla Firefox
      pros, cons and recent comments
      Brings aut of the box what you need and don't support datastealing apps
      Positive comment over 2 years ago

      -1
    • Web-browser, advanced e-mail, newsgroup and feed client, IRC chat, and HTML editing in one application. Itis built on the open source Mozilla Gecko engine, the same code which underlies Thunderbird and is the base for the Firefox browser. View 170 alternatives to SeaMonkey
      Most users think SeaMonkey is a great alternative to Mozilla Firefox.
      • FreeOpen Source
      • Mac
      • Windows
      • Linux
      • BSD
      • PortableApps.com
      SeaMonkey vs Mozilla Firefox
      pros, cons and recent comments
      It's the Father of Firefox and has an EXCELLENT team to keep it up to date and with current Firefox code. I just love this browser. ;)
      Top positive comment  over 2 years ago

      4
      Less resource-intensive than Firefox. Generally fast and stable.
      Top positive comment  about 4 years ago

      3
      I likee SeaMonkey because is lightweight, have add-on support, support old versions of Windows, and as a old-school design that combines with the system i use. Perfect alternative, i recommend giving a try!
      Positive comment 19 days ago

      0
      kompowiec2 Lighweight and is without soros Support.
      Positive comment almost 4 years ago

      -3
      mzs_47 Lighter on resources, had UI we were used to in old Firefox(version 3.x), some features like webRTC might be missing.
      Positive comment over 5 years ago

      2
      Within Linux works much more fast and compatible with Firefox extensions
      Positive comment almost 6 years ago

      2
    • Gnuzilla is the GNU version of the Mozilla suite, and GNU IceCat is the GNU version of the Mozilla Firefox browser. View 148 alternatives to GNU IceCat
      Almost everyone thinks GNU IceCat is a great alternative to Mozilla Firefox.
    Showing 10 of 90 alternatives