Browsers and Email
Two programs cover most of what people need from internet software: a browser and an email client. This category holds the two Mozilla applications that do those jobs, Mozilla Firefox and Mozilla Thunderbird. Both are open source, both are free of charge with no paid tier for the features described here, and both run on Windows, macOS and Linux.
The honest summary before the detail: Firefox is a fast, standards-compliant browser whose default configuration still includes telemetry and a commercial search deal, and Thunderbird is a dependable desktop mail client whose weakest area is Microsoft Exchange. Neither is a hardened privacy tool as shipped, and both can be configured to get close to one.
Details and official download links are on the Mozilla Firefox and Mozilla Thunderbird program pages, so no third-party download portal is involved.
Find your next favourite
Browsers and Email Clients in This Category
Mozilla Firefox
Mozilla Firefox is an open source web browser licensed under MPL-2.0 (Mozilla Public License 2.0) and published by the Mozilla Foundation, with builds for Windows, macOS, Linux, Android and iOS. It renders current web standards well, runs the full extension catalogue including content blockers, and adds tracking protection, while Mozilla's own container extension supplies optional container tabs that keep work and personal logins apart. It suits anyone who wants a mainstream browser they can inspect and configure rather than another Chromium reskin. The weaknesses are real: it usually uses more memory than Chrome or Edge on the same hardware, a few corporate web applications are still tested only against Chromium, and the default setup enables telemetry, sponsored new tab tiles and a search partnership that funds Mozilla. All of those can be switched off in Settings, but you have to switch them off.
Mozilla Thunderbird
Mozilla Thunderbird is the desktop email client from the same project, also licensed under MPL-2.0 and available for Windows, macOS and Linux, plus a separate Android client maintained under the same name. It handles IMAP and POP accounts, multiple identities, a calendar and address book, RSS feeds and newsgroups, and it includes OpenPGP encryption for end-to-end encrypted mail. It suits people who want mail stored locally, strong filtering rules and no subscription. Its weak points are the interface, which still feels denser and older than webmail, slow indexing of very large mailboxes, and Microsoft Exchange support that depends on add-ons. There is no official iOS client.
Comparison Table
| Program | OS | Licence | Best for |
|---|---|---|---|
| Mozilla Firefox | Windows, macOS, Linux, Android, iOS | MPL-2.0 | Everyday browsing with extension control and tracking protection |
| Mozilla Thunderbird | Windows, macOS, Linux, Android | MPL-2.0 | Desktop mail, calendar and OpenPGP in a single local client |
Search Deals, Telemetry and Defaults
Worth stating plainly: no free browser ships an ad-free default search deal. Firefox, Chrome, Edge, Safari and Opera all take money from search providers, and the engine selected on first run reflects that revenue. Mozilla's largest single source of funding is its search agreement with Google, which is why Google is the preselected engine, and Firefox builds also show sponsored shortcuts on the new tab page. Treat the first launch as a configuration task: choose your own default engine, uncheck the sponsored content boxes, and the browser stays free without the commercial defaults.
Telemetry is a separate switch, and in Firefox it is on by default. The Privacy & Security and Search settings pages control technical and interaction data, crash reports, studies and search suggestions. Mozilla collects less than Google does by default and publishes its data collection documentation, but less is not none. Thunderbird has equivalent telemetry and crash report settings, and your mail stays on your own machine unless you point an account at a remote provider.
Good to know
Is Firefox better than Chrome for privacy?
Firefox blocks more trackers out of the box and is not built by an advertising company, so it is the better default. Chrome still collects more and links it to a Google account. Neither is private until you switch off telemetry and add a content blocker.
Does Firefox show ads?
Not inside web pages, but the new tab page can show sponsored tiles and paid search suggestions. Both can be disabled in Settings. The default search engine is also a paid placement rather than a neutral choice.
Is Thunderbird still maintained?
Yes. Mozilla funds Thunderbird through MZLA Technologies Corporation, the desktop client receives regular releases, and a separate Thunderbird for Android client is maintained alongside it.
Can Thunderbird connect to Microsoft 365 or Exchange?
Partly. Modern Thunderbird signs in to Microsoft mail with OAuth2 over IMAP, but Exchange calendars and address books usually need a third-party add-on, and some of those are paid. Test it before you move a work account.
Can I use Firefox and Thunderbird without an account?
Yes. Both work with no Mozilla account at all. An account is only needed for Firefox Sync and for the optional syncing of Thunderbird settings, so mail and browsing stay local without one.