head to head · open source
Zen Browser vs thorium
Zen Browser has 44,481 GitHub stars, 1,754 forks, 689 open issues and last shipped yesterday. thorium has 7,508 stars, 283 forks, 140 open issues and last shipped 26 days ago. Zen Browser leads on adoption by 492% (44,481 vs 7,508 stars). Zen Browser is written in C++ under MPL-2.0; thorium is written in C++ under BSD-3-Clause. Zen Browser has attracted 4% as many forks as stars, thorium 4%. 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 | thorium | |
|---|---|---|
| GitHub stars | ★ 44K | ★ 7.5K |
| License | MPL-2.0 | BSD-3-Clause |
| Written in | C++ | C++ |
| Last push | 2026-09-17 | 2026-08-23 |
| Forks | ⑂ 1.8K | ⑂ 283 |
| 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 thorium if
- You want the thorium feature set and don't need the biggest community
- You prefer the BSD-3-Clause license terms
- Your stack matches C++
- You evaluated both and thorium 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 thorium
Thorium is a BSD 3 Clause licensed Chromium fork, written in C++ and named after radioactive element No. 90, that ships optimised Linux builds here while Windows, macOS, Android and Raspberry Pi builds live in companion repositories.
read the full thorium overview →
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Frequently asked questions
Is Zen Browser or thorium more popular?
Zen Browser has 44,481 GitHub stars and thorium has 7,508. Zen Browser has the larger community by that measure.
Are Zen Browser and thorium free?
Both are open source. Zen Browser is licensed under MPL-2.0 and thorium under BSD-3-Clause. Neither carries a licence fee.
What is the difference between Zen Browser and thorium?
Zen Browser is written in C++ and thorium in C++. 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 thorium?
Choose Zen Browser if you want the larger community (44,481 stars) or its MPL-2.0 licence terms. Choose thorium if its feature set, stack or BSD-3-Clause licence fits better. Both are self-hostable.