Zen Browser is a

free and open-source Free and open-source software (FOSS) is software available under a Software license, license that grants users the right to use, modify, and distribute the software modified or not to everyone free of charge. FOSS is an inclusive umbrella term ...

fork In cutlery or kitchenware, a fork (from 'pitchfork') is a utensil, now usually made of metal, whose long handle terminates in a head that branches into several narrow and often slightly curved tines with which one can spear foods either to h ...

Mozilla Firefox Mozilla Firefox, or simply Firefox, is a free and open-source web browser developed by the Mozilla Foundation and its subsidiary, the Mozilla Corporation. It uses the Gecko rendering engine to display web pages, which implements curren ...

introduced in 2024, with a focus on privacy,

customizability Customization may refer to: *Customization (anthropology), the process of cultural appropriation and creation of bespoke design * Customization (international marketing), a country-tailored product strategy *Mass customization, the use of computer ...

and design. Zen includes many of the layout changes and features associated with the

Chromium Chromium is a chemical element; it has Symbol (chemistry), symbol Cr and atomic number 24. It is the first element in Group 6 element, group 6. It is a steely-grey, Luster (mineralogy), lustrous, hard, and brittle transition metal. Chromium ...

-based

web browser A web browser, often shortened to browser, is an application for accessing websites. When a user requests a web page from a particular website, the browser retrieves its files from a web server and then displays the page on the user's scr ...

Arc. After The Browser Company announced the Arc browser was no longer going to receive new features, Zen has been considered a major alternative and a continuation in spirit. It is licensed under the terms of the

Mozilla Public License The Mozilla Public License (MPL) is a free and open-source weak copyleft license for most Mozilla Foundation software such as Firefox and Thunderbird. The MPL is developed and maintained by Mozilla, which seeks to balance the concerns of bo ...

2.0.

Compatibility

Zen Browser is compatible with

Microsoft Windows Windows is a Product lining, product line of Proprietary software, proprietary graphical user interface, graphical operating systems developed and marketed by Microsoft. It is grouped into families and subfamilies that cater to particular sec ...

macOS macOS, previously OS X and originally Mac OS X, is a Unix, Unix-based operating system developed and marketed by Apple Inc., Apple since 2001. It is the current operating system for Apple's Mac (computer), Mac computers. With ...

and

Linux Linux ( ) is a family of open source Unix-like operating systems based on the Linux kernel, an kernel (operating system), operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically package manager, pac ...

. It had three download options: optimized, made for newer systems; generic, made for older systems; and ARM64, made for devices that run on

ARM64 AArch64, also known as ARM64, is a 64-bit version of the ARM architecture family, a widely used set of computer processor designs. It was introduced in 2011 with the ARMv8 architecture and later became part of the ARMv9 series. AArch64 allows ...

architectures. The optimized version used

Advanced Vector Extensions 2 Advanced Vector Extensions (AVX, also known as Gesher New Instructions and then Sandy Bridge New Instructions) are SIMD extensions to the x86 instruction set architecture for microprocessors from Intel and Advanced Micro Devices (AMD). They were ...

, a

CPU A central processing unit (CPU), also called a central processor, main processor, or just processor, is the primary processor in a given computer. Its electronic circuitry executes instructions of a computer program, such as arithmetic, log ...

instruction set In computer science, an instruction set architecture (ISA) is an abstract model that generally defines how software controls the CPU in a computer or a family of computers. A device or program that executes instructions described by that ISA, s ...

that enhances performance for certain tasks. This instruction set is available only on modern processors. The optimized builds were discontinued in December 2024 due to high power consumption, user confusion, and incompatibility with other

Clang Clang () is a compiler front end for the programming languages C, C++, Objective-C, Objective-C++, and the software frameworks OpenMP, OpenCL, RenderScript, CUDA, SYCL, and HIP. It acts as a drop-in replacement for the GNU Compiler ...

optimizations. The Linux version is available for download as a

Flatpak Flatpak is a utility for software deployment and package management for Linux. It provides a sandbox environment in which users can run application software in (partial) isolation from the rest of the system. Flatpak was known as xdg-app unti ...

AppImage AppImage (formerly known as klik and PortableLinuxApps) is an open-source format for distributing portable software on Linux. It aims to allow the installation of binary software independently of specific Linux distributions. As a result, one App ...

and as a Tarball. The macOS and Windows version are available for

x86_64 x86-64 (also known as x64, x86_64, AMD64, and Intel 64) is a 64-bit extension of the x86 instruction set. It was announced in 1999 and first available in the AMD Opteron family in 2003. It introduces two new operating modes: 64-bit mode a ...

and ARM64.

Features

Being based on Firefox, Zen is compatible with Firefox

browser extension A browser extension is a software module for customizing a web browser. Browsers typically allow users to install a variety of extensions, including user interface modifications, cookie management, ad blocking, and the custom scripting and st ...

s, and offers

browser synchronization A web browser, often shortened to browser, is an application for accessing websites. When a user requests a web page from a particular website, the browser retrieves its files from a web server and then displays the page on the user's screen ...

through a Mozilla account.

Tab management

Zen Browser presents a vertical list of

tabs Tab, TAB, tabs, or TABS may refer to: Places * Tab, Hungary, a town * Tab District, Hungary, whose seat is Tab * Tab, Indiana, United States, an unincorporated community * Arthur Napoleon Raymond Robinson International Airport, Tobago, IATA cod ...

in a sidebar—a design pattern associated with Arc, though also present in earlier browsers such as

Vivaldi Antonio Lucio Vivaldi (4 March 1678 – 28 July 1741) was an Italian composer, virtuoso violinist, impresario of Baroque music and Roman Catholic priest. Regarded as one of the greatest Baroque composers, Vivaldi's influence during his lif ...

and

Microsoft Edge Microsoft Edge is a Proprietary Software, proprietary cross-platform software, cross-platform web browser created by Microsoft and based on the Chromium (web browser), Chromium open-source project, superseding Edge Legacy. In Windows 11, Edge ...

. This sidebar can be displayed on the left or right side of the

window A window is an opening in a wall, door, roof, or vehicle that allows the exchange of light and may also allow the passage of sound and sometimes air. Modern windows are usually glazed or covered in some other transparent or translucent ma ...

, and there is a Compact Mode that auto-hides it. Zen can be partitioned into workspaces, which separates tabs within the same window and shows one set at a time, allowing for grouping by topic or project. Similarly to

Opera Opera is a form of History of theatre#European theatre, Western theatre in which music is a fundamental component and dramatic roles are taken by Singing, singers. Such a "work" (the literal translation of the Italian word "opera") is typically ...

, tabs can be pinned to specific workspaces, whereas Essential tabs remain visible across them. Tabs in the same workspace can be displayed together in Split View, a tiled interface within a single Zen window. Glance opens a link in a modal view that is more easily dismissed than a new tab. It is invoked by clicking a link while holding a

modifier key In computing, a modifier key is a special key (or combination) on a computer keyboard that temporarily modifies the normal action of another key when pressed together. By themselves, modifier keys usually do nothing; that is, pressing any of the , ...

. The feature is based on Arc's Peek function (confused with tabless "Little Arc" windows in several reviews). Zen Sidebar is a detachable mobile-sized window, useful for viewing responsive websites compactly.

Customization

Zen Browser's

user interface In the industrial design field of human–computer interaction, a user interface (UI) is the space where interactions between humans and machines occur. The goal of this interaction is to allow effective operation and control of the machine fro ...

can be themed with

color gradient In color science, a color gradient (also known as a color ramp or a color progression) specifies a range of position-dependent colors, usually used to fill a region. In assigning colors to a set of values, a gradient is a continuous colormap, ...

s and texture. Zen Mods (formerly called Themes Store) is a collection of

user-generated User-generated content (UGC), alternatively known as user-created content (UCC), emerged from the rise of web services which allow a system's users to create content, such as images, videos, audio, text, testimonials, and software (e.g. video ...

theme Theme or themes may refer to: * Theme (Byzantine district), an administrative district in the Byzantine Empire governed by a Strategos * Theme (computing), a custom graphical appearance for certain software. * Theme (linguistics), topic * Theme ( ...

add-ons designed to further customize Zen's interface. As of February 12, 2025, 79 mods are available.

Reception

Zen Browser has been commended for its similar feature set to Arc in an open-source, non-Chromium environment, and for iterating on Firefox during a period of perceived stagnation. Liam Proven from ''

The Register ''The Register'' (often also called El Reg) is a British Technology journalism, technology news website co-founded in 1994 by Mike Magee (journalist), Mike Magee and John Lettice. The online newspaper's Nameplate_(publishing), masthead Logo, s ...

'' praised Zen for being "free of

Google Google LLC (, ) is an American multinational corporation and technology company focusing on online advertising, search engine technology, cloud computing, computer software, quantum computing, e-commerce, consumer electronics, and artificial ...

code", having more usable implementations of Arc's features, and being compatible with older versions of

operating system An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for ...

s, focusing on the vertical tab bar and tiling capabilities. Jack Wallen of '' ZDNet'' recommended Zen for improving on Firefox's customization and tab management, listing several Zen Mods to indicate its customizability. Writing for '' XDA'', Adam Conway considered Zen to "combine the best of

Floorp Floorp is a free and open-source web browser based on Firefox. Features Floorp was based on Chromium in the past, but due to some technical issues, it has been based on Firefox since version 7.0.0. It is based on the Firefox ESR (Extended Sup ...

, Vivaldi, Firefox, and Chrome", noting the developer's willingness to add popularly requested features, and emphasizing the browser's detachment from

's " web rendering monopoly". Conway described incompatibility with

DRM DRM may refer to: Government, military and politics * Defense reform movement, U.S. campaign inspired by Col. John Boyd * Democratic Republic of Madagascar, a former socialist state (1975–1992) on Madagascar * Direction du renseignement militair ...

-protected content as the "only major downside", while suggesting that

software bug A software bug is a design defect ( bug) in computer software. A computer program with many or serious bugs may be described as ''buggy''. The effects of a software bug range from minor (such as a misspelled word in the user interface) to sev ...

s that had drawn earlier criticism had been corrected.

References

External links

* * {{Web browsers, active Web browsers based on Firefox Web browsers Software forks Linux web browsers MacOS web browsers Windows web browsers Software using the Mozilla Public License