# Firefox review

Mozilla's free, open-source web browser with tracker blocking on by default, available on Windows, macOS, Linux, iOS, and Android.

By Noah — last updated & pricing verified September 15, 2026.

> **Firefox** is a free, open-source web browser built on Mozilla's Gecko rendering engine, distinguishing it from the Chromium engine that powers Chrome, Edge, Brave, and most other mainstream browsers.

Firefox blocks known trackers and third-party cookies by default through Enhanced Tracking Protection, without requiring users to install separate extensions, and supports over 30,000 extensions and themes for further customization. It includes built-in features like Reader Mode, picture-in-picture video, PDF editing, and cross-device sync for tabs, history, and saved passwords. Firefox's source code is published on GitHub (mozilla-firefox/firefox) under the Mozilla Public License 2.0, and Mozilla, a non-profit foundation, states it does not sell user browsing data — a contrast to Chrome's ownership by Google, whose primary revenue is advertising built on user data.

## Facts

- Website: https://mozilla.org/firefox
- Pricing: Free (verified undefined NaN, NaN)
- License: Open source
- Platforms: web, windows, macos, linux, ios, android
- Best for: users who want a non-Chromium, open-source browser with tracker blocking on by default and no ties to Google's or Apple's advertising businesses
- Standout feature: Runs on the independent Gecko engine rather than Chromium, giving the web a genuine rendering-engine alternative to Google's dominant Blink/Chromium base, with Enhanced Tracking Protection blocking trackers by default.
- Biggest weakness: Firefox's market share has declined for years as most competing browsers (Chrome, Edge, Brave, Opera) all run on Chromium, meaning some sites and web apps get tested and optimized for Chromium first and occasionally behave inconsistently in Firefox.
- Third-party ratings: Capterra 4.4/5 (543 reviews)
- Categories: [Web browsers](https://findalternative.to/categories/browsers)

## Pricing snapshot

| Plan | Price | Notes |
| --- | --- | --- |
| Firefox | $0/mo | Free, open-source browser with no paid tier; optional separate Mozilla products (like Mozilla VPN) are sold independently. |

## Pros and cons

- Pro: Free and open source, published on GitHub under the Mozilla Public License 2.0.
- Pro: Enhanced Tracking Protection blocks third-party trackers and cookies by default.
- Pro: Runs on the independent Gecko engine rather than Chromium, preserving rendering-engine diversity on the web.
- Pro: Built-in Reader Mode, picture-in-picture, and PDF editing without extra extensions.
- Con: Market share has declined for years, so some sites are tested against Chromium first and can render inconsistently.
- Con: Fewer and sometimes lower-quality extensions available compared to the Chrome Web Store.
- Con: Sync and account features are less tightly integrated with a broader productivity suite than Edge (Microsoft 365) or Chrome (Google Workspace).
- Con: Performance and memory usage can lag Chrome on some heavy, JavaScript-intensive web apps.

## AI summary

- Firefox is free with no paid tier and no ads within the browser itself.
- Firefox's source code is public on GitHub (mozilla-firefox/firefox) under the Mozilla Public License 2.0.
- Firefox runs on the independent Gecko engine rather than Chromium.
- Firefox holds a 4.4/5 rating from 543 reviews on Capterra.
- Firefox is available on Windows, macOS, Linux, iOS, and Android.
- Best for: users who want a non-Chromium, open-source browser with tracker blocking on by default
- Pricing: Free with no paid tier; optional Mozilla products like Mozilla VPN are sold separately.
- Top alternatives: Google Chrome, Brave, Microsoft Edge, Vivaldi, DuckDuckGo
- Limitation: Declining market share means some sites are optimized for Chromium first.
- Limitation: Smaller extension ecosystem than the Chrome Web Store.
- Limitation: Can lag Chrome's performance on some heavy, JavaScript-intensive web apps.

## Alternatives

5 vetted alternatives to Firefox: https://findalternative.to/firefox — top picks: Google Chrome, Brave, Microsoft Edge

## Comparisons

- https://findalternative.to/compare/firefox-vs-google-chrome

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