Open Source Browser Guide | Generated by AI
Question: What are good open source browsers to use, and does Safari open source any of its components?
Answer:
Open Source Browsers Worth Using
Tier 1 — Daily-driver quality
Firefox (Mozilla)
- Fully open source (MPL 2.0), own engine: Gecko + SpiderMonkey (JS)
- Repo: github.com/mozilla/gecko-dev
- Only major non-Chromium engine left standing (besides WebKit)
- Good for: privacy, devtools, extensions, non-Google engine diversity
Brave
- Open source (MPL 2.0), Chromium-based (Blink engine)
- Repo: github.com/brave/brave-browser
- Brave blocks harmful advertising, tracking pixels and cookies, and redirects sites to HTTPS. Available for macOS, Windows, and Linux.
- Many now argue that Brave has taken Firefox’s former top spot in the open source world.
- Good for: daily use, built-in ad block, Chromium compat, no Google tracking
Chromium
- The upstream of Chrome, fully open source
- Repo: chromium.googlesource.com/chromium/src
- Good for: debugging web apps exactly as Chrome renders them, without Google telemetry
Tier 2 — Developer/Niche
ungoogled-chromium
- Chromium with all Google API calls stripped
- Repo: github.com/ungoogled-software/ungoogled-chromium
Ladybird (most exciting technically)
- A new browser built on a completely original engine — shares no code with Blink, WebKit, Gecko, or any other existing engine. Non-profit backed, funded entirely through donations and sponsorships, with no search deals, no data collection, and no advertising. A first Alpha release is targeting Linux and macOS in 2026, aimed at developers and early adopters. Eight full-time engineers are working on it alongside community contributors. Recent updates include an inline PDF viewer, browsing history, HTTP caching, media streaming, CSS anchor positioning, off-thread JS compilation, and a new regex engine.
- This is the most architecturally interesting one right now — worth watching.
Safari and Open Source
Safari itself (the app shell, UI, sync, etc.) is closed source proprietary. But its two core engines are open source:
WebKit — the rendering/layout engine
- WebKit is an open source web content engine for browsers and other applications. Apple developed and open-sourced it. The WebKit project prioritizes real-world web compatibility, standards compliance, stability, performance, battery life, security, privacy, portability, and hackability.
- Repo: github.com/WebKit/WebKit
- License: LGPL 2.1 (WebCore) + BSD (JavaScriptCore)
Components inside WebKit:
- WebCore — HTML/CSS layout and rendering (the DOM, painting pipeline)
- JavaScriptCore (JSC) — Apple’s JS engine, equivalent to V8/SpiderMonkey
- Both have been open since 2005. In June 2005, Apple announced it was open-sourcing the entirety of WebKit (previously only WebCore and JavaScriptCore were open source), reportedly as part of an effort to work more closely with KDE and the open-source community.
What’s closed: Safari’s UI, iCloud sync, Handoff, Keychain integration, Private Relay — all proprietary.
Quick Reference
| Browser | Engine | Open Source | Notes |
|---|---|---|---|
| Firefox | Gecko/SpiderMonkey | ✅ Full | Only major non-Blink/WebKit engine |
| Brave | Blink/V8 | ✅ Full | Best daily-driver for privacy |
| Chromium | Blink/V8 | ✅ Full | Chrome upstream |
| ungoogled-chromium | Blink/V8 | ✅ Full | Chromium - Google telemetry |
| Ladybird | LibWeb (custom) | ✅ Full | New from scratch, alpha 2026 |
| Safari | WebKit/JSC | ❌ App, ✅ Engine | WebKit/JSC are open source |
| Chrome | Blink/V8 | ❌ Closed | Built on open Chromium |
My recommendation for you: Brave or ungoogled-chromium for daily use. Ladybird is worth cloning and running just to see what building a browser engine from scratch looks like — very Karpathy-style learning.
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