Mozilla Firefox

ApplicationMozilla Corporation

Also called firefox, mozilla firefox, ff

Mozilla CorporationBrowsers

Mozilla's Gecko browser. On Windows the process is firefox.exe, with extra copies for content and GPU work.

What you need to know

Firefox is Gecko. Chrome and Edge are Chromium. The process name is firefox.exe.

Mozilla Firefox is an independent browser engine. Extra firefox.exe rows are content processes. It is not a Chrome reskin and it is not msedge.exe.

What is it?: A Gecko web browser
Many processes?: Yes. Multiprocess Firefox
Same as Chrome?: No. Different engine

Feex says

If you want a browser that is not Chromium, this is the common one Feex actually sees on Windows PCs. I still would not call the extra processes a virus.

What is Mozilla Firefox?

Mozilla Firefox is a Gecko-based web browser. The Windows executable is firefox.exe. Profiles live under AppData, not in System32.

If you have never used it

If you want a browser that is not Chrome and not Edge, Firefox is the common independent one. Install it from mozilla.org/firefox. It syncs through a Firefox account, not a Google account. Extra firefox.exe rows are content processes, the same idea as Chromium tabs with a different engine.

What is it used for?

Web browsing

Daily tabs on Gecko. Site compatibility is usually fine and not identical to Chrome.

Containers and strict tracking protection

Multi-Account Containers keep cookies apart. This is a Firefox feature Chrome does not ship the same way.

Extensions

Add-ons from addons.mozilla.org. A Chrome Web Store item does not install here.

Who is it for?

People who want a non-Chromium engine
Users who already have a Firefox account and sync
Anyone comparing browsers without treating process count as a risk score

Current status

Actively developed. Mozilla ships Rapid Release and Extended Support Release. This article is the desktop Windows browser, not Firefox for Android.

How old is it?

Firefox 1.0 shipped in 2004. The project grew out of Mozilla and Netscape work that started in the late 1990s. It is an old, still-current browser. Phoenix and Firebird were early names. Those are not what you install today.

Versions

Major channels first. Exact build numbers are not all verified here.

Rapid Release

ESR

Beta

Nightly

System requirements

Values follow the publisher's public guidance. Workload still changes the real need.

Minimum

Minimum system requirements
CPU	A 64-bit processor supported by current Firefox, per Mozilla
RAM	Mozilla lists 2 GB class machines. More tabs want more RAM
Operating system	A current supported Windows 10 or Windows 11 release, per Mozilla

Resource profile

CPU demand: Follows the heaviest tab
RAM demand: Content processes and trackers
GPU demand: WebRender and video

Installed processes

These executables belong to this product when it is installed.

Installed processes
firefox.exe	Parent, content, and GPU processes

Startup components

Firefox can restore the previous session. That is a Firefox setting, not a Windows service.

File locations

Common Mozilla Firefox locations
Typical install	C:\Program Files\Mozilla Firefox\
Profile	C:\Users\<you>\AppData\Roaming\Mozilla\Firefox\Profiles\

File formats

HTMLPDFPNGJPEG

Common problems

Memory after many containers

Containers add isolation. about:processes is the Firefox-specific map.

People compare only process counts

Chromium browsers also multiply processes. Count is not a malware score.

Getting unstuck

Open about:processes

That page names content processes. Ending a random firefox.exe in Task Manager can close the wrong tab.

Refresh or a new profile before a Windows reinstall

about:support has Refresh Firefox. Profiles live under AppData\Roaming\Mozilla\Firefox.

Install only from mozilla.org

Search ads for "Firefox free" are a common junk path. The real download is on Mozilla's site.

Alternatives

Chrome, Edge, and Brave cover the same daily job with a different engine. Pick them for sync and site compatibility, not because a filename mill ranked them.

Official help and downloads

Start with the vendor. Random exe sites are not a support channel.

Official contacts
Download	www.mozilla.org/firefox/ Official Windows installer
Support	support.mozilla.org/products/firefox Account, sync, and crash help
System requirements	www.mozilla.org/firefox/system-requirements/ What Mozilla lists for current Windows
Add-ons	addons.mozilla.org/ Extensions. Not a Chrome Web Store mirror
Release notes	www.mozilla.org/firefox/releases/ What changed in a Rapid Release

Related hardware

RAM and a current GPU driver matter more than a famous CPU name. Firefox WebRender wants a working GPU.

Technical details

Release numbers change every four weeks on Rapid Release. This article does not pin a build.

Sources and verification

Reviewed by Feex editorial. Last verified August 2026 Status: Feex Reviewed. How we research.

Mozilla Firefox · Official product
Mozilla Support: system requirements · Windows requirements
Foxhole process map · First-party samples on Windows PCs. Not a lab benchmark.

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