Flecha vs Zen Browser
Zen and Flecha are the two open-source browsers most like Arc. The biggest difference is underneath: Zen is a Firefox fork, Flecha is a Chromium fork. That decides which extensions you can use and how sites behave.
At a glance
Section titled “At a glance”| Flecha | Zen | |
|---|---|---|
| Engine | Chromium (Blink) | Firefox (Gecko) |
| License | MIT | MPL-2.0 |
| Platforms | macOS | macOS, Windows, Linux |
| Extensions | Chrome Web Store | Firefox add-ons |
| Sidebar and Spaces | Spaces, optionally with separate cookies | Workspaces |
| Link preview | Peek | Glance |
| Split view | Two panes | Yes |
| Arc import | Spaces, pinned tabs, folders, favorites, history | No Arc sidebar import |
| Ad blocking | Built in | Through an add-on such as uBlock Origin |
| Developer command bar | gh, npm, mdn, caniuse, JWT and timestamp decoding |
No |
| Coding agents | Built-in MCP server | No |
Choose Zen if
Section titled “Choose Zen if”- you’re on Linux or Windows,
- you prefer Firefox’s engine, or rely on Firefox-only add-ons,
- you want deep customisation through Firefox’s settings and mods.
Choose Flecha if
Section titled “Choose Flecha if”- you’re on a Mac and want pages to render exactly as in Chrome, the browser most sites are tested on,
- you need Chrome extensions, such as a password manager that talks to its desktop app,
- you want to bring your Arc Spaces and pinned tabs over in one step,
- you build websites: environments, a phone view and your dev servers in the sidebar, plus MCP for coding agents.