Firefox

Best for: most people who want a private-leaning browser that isn’t Chromium, with real extension support and sane defaults — and who accept that the strongest settings, and turning off the sponsored bits, are a few clicks away.

Pros

• Enhanced Tracking Protection is on by default: it blocks cross-site tracking cookies, social-media trackers, known fingerprinting scripts, and cryptominers using Disconnect’s list
• Total Cookie Protection is on in the default Standard mode, giving every site its own isolated cookie jar so cookies can’t follow you between sites
• Page loads are upgraded to HTTPS by default (since Firefox 136), with a silent fallback if a site doesn’t support it
• The only mainstream browser not built on Chromium — it runs its own Gecko engine, so it’s a genuine counterweight to Google’s control of web-platform direction
• Full extension support, including content blockers and privacy add-ons that the Chromium world has cut back under Manifest V3
• Firefox Sync is end-to-end encrypted: the encryption key is derived from your account password and never sent to Mozilla, so Mozilla can’t read your synced bookmarks, history, or passwords
• Fully open source under the MPL 2.0, with the entire codebase public
• Available on all five major platforms, and Mozilla is a non-profit-owned organisation rather than an ad company or a VC-backed startup

Cons

• Around 85% of Mozilla’s revenue comes from the deal that makes Google the default search engine in Firefox — the browser’s funding depends on the company whose ad-tracking business its privacy features push against
• Telemetry is opt-out, not absent: “technical and interaction data” goes to Mozilla until you turn it off, and a separate de-identified daily usage ping has its own opt-out
• The New Tab page shows sponsored content and Firefox fetches sponsored search suggestions in the US and some regions — both on by default
• Fingerprinting protection in the default mode is only a block-list of known fingerprinters; there’s no unified anti-fingerprinting profile without going into Strict or about:config, so the passive fingerprinting surface a stock Firefox exposes is largely unaddressed
• Global Privacy Control exists but is off by default, and tracking content is blocked only in private windows unless you switch to Strict
• Ships a Mozilla-account “VPN” that only proxies Firefox’s own traffic, not the whole device — useful to know, but not a real VPN
• Trust history: a February 2025 Terms of Use update with a broad data-license clause (walked back after backlash) and a 2017 episode where Mozilla pushed a promotional add-on into browsers unprompted
• Sync encryption is tied to the account password with no separate passphrase, and changing that password without a local copy of your data can leave it unrecoverable — a pattern that shows up repeatedly in user complaints
• No published independent security audit of the browser build itself

Privacy Defaults

Out of the box, Firefox is meaningfully more private than a default Chromium browser. Enhanced Tracking Protection runs in Standard mode from the first launch: cross-site tracking cookies, social-media trackers, known fingerprinters, and cryptominers are blocked against Disconnect’s list, and Total Cookie Protection isolates every site’s cookies so they can’t be used to join up your browsing. HTTPS-First upgrades connections automatically. None of this needs setup.

The reasons it isn’t the most private state: telemetry is opt-out rather than off, so technical and interaction data flows to Mozilla until you visit settings; the New Tab page carries sponsored content and Firefox pulls sponsored suggestions in the US by default; Global Privacy Control is present but unchecked; and in Standard mode, tracking content hidden inside ads and videos is only blocked in private windows. Switching ETP to Strict closes most of those gaps but breaks more sites. The default is a solid privacy baseline that a few minutes of configuration turns into a strong one.

Anti-Fingerprinting

This is Firefox’s weakest privacy area in its default configuration. Standard mode blocks a list of known fingerprinting scripts, which stops the worst offenders but does nothing about the passive surface — canvas, WebGL, fonts, screen metrics, audio stack — that any site can read. The broader “limit what the browser exposes” behaviour, covering suspected fingerprinters, only turns on in Private Browsing or Strict mode.

Firefox does have a stronger resist-fingerprinting capability, but it lives behind Strict/Custom settings and about:config rather than the default UI, and it comes with visible breakage: custom fonts get ignored, some video effects misbehave, window sizing changes, complex pages run slower. Mozilla’s own documentation frames the default behaviour as limiting what the browser exposes to suspected fingerprinters only in private windows or Strict mode — meaning that in ordinary browsing, canvas, WebGL, font, and audio-stack readouts remain available to any site. For a determined tracker, the default Firefox is identifiable; the tools to change that exist but are opt-in and disruptive.

Transparency & Audits

The code is fully open under the MPL 2.0, the whole codebase is public, and Mozilla is owned by a non-profit foundation rather than investors or an ad company — a structurally cleaner setup than most. Mozilla also publishes audited financials each year, so the money is visible.

Two things weigh against that. First, what the money says: roughly 85% of Mozilla’s revenue is the payment that makes Google the default search engine in Firefox, and a 2024 antitrust ruling against Google put that arrangement — and, by Mozilla’s own board’s account, Mozilla’s viability — at risk before a 2025 remedy left it intact. A privacy browser financed almost entirely by the dominant ad-tracking company is a real tension, even if it doesn’t change what the browser does. Second, trust history: in February 2025 Mozilla added Terms of Use with a broad “nonexclusive, royalty-free, worldwide license” to user-input data and quietly dropped an FAQ promise not to sell data, then reversed course after backlash and restored explicit “we don’t sell your data” wording. In 2017 it pushed a promotional browser extension to users without asking. Both were walked back, but on a browser sold on privacy they count. There is also no published independent security audit of the Firefox build itself — the review posture is the open codebase, a bug-bounty program, and Mozilla’s internal security team.

Usability & Compatibility

Firefox is a mainstream daily driver and behaves like one. It’s a mature browser with its own engine, so site compatibility is good, DRM video plays, and the developer tools are strong — many developers prefer them to Chromium’s. Crucially, it still supports full-capability extensions, so content blockers and privacy add-ons that were cut down elsewhere under Manifest V3 keep working here.

The friction is around updates. Firefox updates frequently, and a recurring complaint — visible across user reviews after the mid-2026 releases — is that updates disrupt saved state: bookmarks, passwords, and open tabs going missing, and personalised toolbar settings resetting. Mozilla has also drawn criticism for adding AI features and sponsored surfaces that some long-time users see as clutter. None of this makes the browser hard to use, but the “it changed my setup again” experience is common enough to note.

Cross-Platform & Sync

Firefox has official builds for Windows, macOS, Linux, Android, and iOS (WebKit-bound on iOS like every browser there). Sync is end-to-end encrypted: your Mozilla account password is key-stretched into an authentication key that goes to the server and an encryption key that never does, so Mozilla can’t decrypt your bookmarks, history, tabs, or passwords.

The weak point is that the encryption is tied to the account password itself — there’s no separate sync passphrase. Mozilla’s own documentation says the protection is only as strong as that password, and in practice, changing the account password without a device that still holds your data locally can leave synced data unrecoverable. Several user complaints describe exactly that outcome. It’s genuinely private against Mozilla, but less robust as a design than a browser that uses a dedicated, separately-managed sync key.

Our Rating

Category	Score
Privacy Defaults	7.5/10
Anti-Fingerprinting	4.5/10
Transparency	6.5/10
Usability & Compatibility	8/10
Cross-Platform & Sync	8/10
Overall	6.7/10

Weighted: Privacy Defaults 30% · Anti-Fingerprinting 25% · Transparency 20% · Usability & Compatibility 15% · Cross-Platform & Sync 10%.

Firefox is the browser to reach for if you want off Chromium without giving up extensions, sites that work, or a familiar experience — and its defaults genuinely protect you more than a mainstream Chromium browser does. It’s held back by a fingerprinting defense that’s only a block-list unless you accept Strict-mode breakage, telemetry and sponsored surfaces that are on until you turn them off, and a funding model that ties a privacy browser to the search-ad giant. For most people who want a private-leaning daily driver and will spend ten minutes in settings, Firefox is a sound choice. If you want the defaults to already be the hardened option, that’s what the Firefox-based forks exist for.

Affiliate Disclosure

Firefox has no affiliate program for websites like ours, and this review carries no tracked link — the “Visit Site” button points to Firefox’s plain download page and earns us nothing. Our rating and what we write are unaffected either way.

Rating: 6.7/10