Zen alternatives.

Arc is The Browser Company’s Chromium browser for Mac and Windows that put tabs down the side, with spaces, folders and Split View. It has had no new features since May 2025; it still gets security fixes, and its makers point people to Dia.

Keeps: tabs down the side, spaces, folders in the sidebar, Split View, a Windows version and a free price.

Pick it if you use it today and want its sidebar, spaces and Split View exactly as they are. The catch: No new features since May 2025, only security updates.

Vivaldi is a Chromium browser with a setting for nearly everything, mail, calendar and feeds built in, a free Proton VPN and no AI by design, on every desktop and phone.

Keeps: tabs down the side (as a setting), spaces, folders in the sidebar, Split View, a Windows version and a free price.

Pick it if you want mail, calendar, feeds, notes and a VPN in the browser. The catch: No AI assistant or agent, by design.

Aside is an AI agent browser from a Y Combinator startup, on Chromium, for Mac and Windows. Its agent does multi-step work in the sites you are signed in to, on Aside’s own models or your ChatGPT or Claude plan.

Keeps: tabs down the side, spaces, folders in the sidebar, Split View, a Windows version and a free price.

Pick it if you want an agent for multi-step work across your signed-in sites, on Mac or Windows. The catch: The free plan has 500 AI credits a month; more is Pro at $20 or Max at $200.

SigmaOS is a Mac browser on WebKit that treats tabs like a to-do list, in workspaces down the side, with an AI assistant called Airis.

Keeps: tabs down the side, spaces, Split View and a free price. Misses: folders in the sidebar and a Windows version.

Pick it if you want workspaces and tabs you mark done, on a Mac. The catch: Mac only.

Edge is Microsoft’s Chromium browser on every desktop and phone, with Copilot built in. Since Copilot Mode was retired in May 2026, its agent, Browse with Copilot, comes with Microsoft 365 Premium in the US.

Keeps: tabs down the side (as a setting), spaces, folders in the sidebar, Split View, a Windows version and a free price.

Pick it if you use Microsoft 365 and want Copilot in the browser. The catch: Browse with Copilot needs Microsoft 365 Premium ($19.99 a month) and is US only.

Opera One is Opera’s free Chromium browser on every desktop and phone, with a free browser VPN, an ad blocker, messengers in the sidebar and Opera AI. Its agents are in a separate browser, Opera Neon.

Keeps: tabs down the side (as a setting), spaces, folders in the sidebar, Split View, a Windows version and a free price.

Pick it if you want a free browser VPN and an ad blocker built in. The catch: Opera AI only chats and sums up; agents need Opera Neon at $19.90 a month.

Dia is the AI browser The Browser Company builds now instead of Arc. It is Chromium-based, for Macs with Apple silicon and, since October 2026, Windows, and its AI chats with your tabs and the tools you connect.

Keeps: tabs down the side (as a setting), spaces, folders in the sidebar, Split View, a Windows version and a free price.

Pick it if you want the current browser from Arc’s makers, with Arc import and tabs down the side as a setting. The catch: AI costs $20 or $100 a month for new users; the free plan has none after a 14-day trial.