In-Depth Review

Zen is the new kid on the browser block, and it's making waves for good reason. Built on Firefox's Gecko engine (not Chromium), Zen combines Arc's innovative sidebar design with Firefox's open-source privacy foundation. The result is a browser that feels fresh, looks beautiful, and doesn't contribute to Google's browser monopoly.

Zen's design philosophy is "calm." The default color scheme is muted, animations are slow and deliberate, and the interface fades away when you're not interacting with it. Compared to Chrome's busy, corporate aesthetic, Zen feels like a mindfulness app that happens to browse the web. For deep work sessions—writing, coding, research—this calm design genuinely reduces distraction.

The sidebar tabs and workspaces are clearly inspired by Arc, but Zen adds its own touches: compact mode completely hides the sidebar until you hover, workspaces can have custom icons and colors, and the split view (while not as polished as Arc's) is functional. If you want Arc's workflow but prefer Firefox over Chromium, Zen is currently your best option.

The trade-off: Zen is still young. As of mid-2026, it lacks an iOS or Android version, some websites render slightly differently than on Chromium browsers, and the extension ecosystem (while compatible with Firefox add-ons) is smaller than Chrome's. Zen is perfect for early adopters and privacy enthusiasts—but mainstream users who need rock-solid reliability should stick with Arc or Brave for now.

Pros

Built on Firefox (Gecko)—not Chromium, so real browser diversity
Calm, beautiful design that reduces visual noise
Open source with an active community

Cons

Smaller user base—fewer tutorials and community resources
Still maturing—occasional bugs and missing features
No iOS/Android version yet