head to head · open source
uBlock vs Zen Browser
uBlock has 69,033 GitHub stars, 4,427 forks, 15 open issues and last shipped yesterday. Zen Browser has 45,517 stars, 1,946 forks, 689 open issues and last shipped yesterday. uBlock leads on adoption by 52% (69,033 vs 45,517 stars). uBlock is written in JavaScript under GPL-3.0; Zen Browser is written in C++ under MPL-2.0. uBlock has attracted 6% as many forks as stars, Zen Browser 4%. uBlock was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 1 topic tag (firefox), so they are genuine substitutes rather than adjacent tools.
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
| uBlock | Zen Browser | |
|---|---|---|
| GitHub stars | ★ 69K | ★ 46K |
| License | GPL-3.0 | MPL-2.0 |
| Written in | JavaScript | C++ |
| Last push | 2026-11-02 | 2026-11-02 |
| Forks | ⑂ 4.4K | ⑂ 1.9K |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick uBlock if
- You weight community size — 69K stars and counting
- You want the GPL-3.0 license terms
- Your stack matches JavaScript
- You value the larger contributor base for long-term maintenance
pick Zen Browser if
- You want the Zen Browser feature set and don't need the biggest community
- You prefer the MPL-2.0 license terms
- Your stack matches C++
- You evaluated both and Zen Browser fits your workflow better
About uBlock
[![Badge Commits]][Commit Rate] [![Badge Issues]][Issues] [![Badge Localization]][Crowdin] [![Badge License]][License] [![Badge NPM]][NPM] [![Badge Mozilla]][Mozilla] ![Badge Chrome] [![Badge Edge]][Edge] uBlock Origin (uBO) GitHub Releases Stable and development versions on Firefox, Chromium MV2, and Thunderbird. Must be placed manually into web browsers; the Chromium and Thunderbird versions usually won't auto update. Related: uBlock Origin Lite uBlock Origin (uBO) is a CPU and memory efficient [wide spectrum content blocker][Blocking] for Chromium and Firefox. It blocks ads, trackers, coin miners, popups…
read the full uBlock overview →
About Zen Browser
Zen Browser Zen is a firefox based browser with the aim of pushing your productivity to a new level! Download • Website • Documentation • Release Notes Firefox Versions Release Is currently built using Firefox version 155.0.1 ! Twilight Is currently built using Firefox version RC 155.0.1 ! Contributing If you'd like to report a bug, please do so on our GitHub Issues page and for feature requests, you can use GitHub Discussions. Zen is an open source project, and we welcome contributions from the community! Please take a look at the contribution guidelines before getting started! Partners Thanks to all the…
read the full Zen Browser overview →
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Frequently asked questions
Is uBlock or Zen Browser more popular?
uBlock has 69,033 GitHub stars and Zen Browser has 45,517. uBlock has the larger community by that measure.
Are uBlock and Zen Browser free?
Both are open source. uBlock is licensed under GPL-3.0 and Zen Browser under MPL-2.0. Neither carries a licence fee.
What is the difference between uBlock and Zen Browser?
uBlock is written in JavaScript and Zen Browser 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, uBlock or Zen Browser?
Choose uBlock if you want the larger community (69,033 stars) or its GPL-3.0 licence terms. Choose Zen Browser if its feature set, stack or MPL-2.0 licence fits better. Both are self-hostable.