head to head · open source
Zen Browser vs opal
Zen Browser has 44,486 GitHub stars, 1,755 forks, 689 open issues and last shipped yesterday. opal has 4,926 stars, 336 forks, 152 open issues and last shipped 5 days ago. Zen Browser leads on adoption by 803% (44,486 vs 4,926 stars). Zen Browser is written in C++ under MPL-2.0; opal is written in Ruby under MIT. Zen Browser has attracted 4% as many forks as stars, opal 7%. Zen Browser was the more recently maintained of the two, and both are self-hostable with no licence fee.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
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Side by side
| Zen Browser | opal | |
|---|---|---|
| GitHub stars | ★ 44K | ★ 4.9K |
| License | MPL-2.0 | MIT |
| Written in | C++ | Ruby |
| Last push | 2026-09-17 | 2026-09-13 |
| Forks | ⑂ 1.8K | ⑂ 336 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Zen Browser if
- You weight community size — 44K stars and counting
- You want the MPL-2.0 license terms
- Your stack matches C++
- You value the larger contributor base for long-term maintenance
pick opal if
- You want the opal feature set and don't need the biggest community
- You prefer the MIT license terms
- Your stack matches Ruby
- You evaluated both and opal fits your workflow better
About Zen Browser
Zen Browser is a privacy focused, open source web browser built on Firefox’s Gecko engine. It inherits Firefox’s compatibility and extension ecosystem while introducing a streamlined interface and productivity oriented features. The project lives in the desktop browser ecosystem, targeting users who want a Firefox based experience with reduced clutter and enhanced customization.
read the full Zen Browser overview →
About opal
Opal is an MIT licensed Ruby to JavaScript source to source compiler, distributed as a Ruby gem, that lets developers write Ruby and run the resulting JavaScript in the browser, Node.js, Deno, Bun, or QuickJS.
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Frequently asked questions
Is Zen Browser or opal more popular?
Zen Browser has 44,486 GitHub stars and opal has 4,926. Zen Browser has the larger community by that measure.
Are Zen Browser and opal free?
Both are open source. Zen Browser is licensed under MPL-2.0 and opal under MIT. Neither carries a licence fee.
What is the difference between Zen Browser and opal?
Zen Browser is written in C++ and opal in Ruby. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, Zen Browser or opal?
Choose Zen Browser if you want the larger community (44,486 stars) or its MPL-2.0 licence terms. Choose opal if its feature set, stack or MIT licence fits better. Both are self-hostable.