Ultralight Web Browser ✨

Ultra‑fast / Ultra‑light / Ultra‑portable

A native C++ proof‑of‑concept browser focused on minimal overhead, cold‑start speed, and resource efficiency.
No multi‑process bloat, no background daemons, no gigabytes of RAM for a handful of tabs—just a lean renderer + native UI.

Download: Ultralight Web → Browser Releases Page | Status: Development / Experimental / Educational

🧭 Table of Contents

Why Ultralight?
Project Philosophy & Goals
Supported Platforms & Architectures
Get the App
Installation
Features
Recent Updates
Tech Stack
Build From Source
ARM64 Build Notes
JavaScript Bridge API
Create Packages Locally
CI / Automation
Roadmap
Troubleshooting
Contributing
Security & Privacy
License
Acknowledgements
Disclaimer

🚀 Why Ultralight? Ditch the Bloat

Traditional browsers (and desktop web stacks like Electron / CEF) embed full, sandboxed operating systems (Chromium). They are powerful—but heavy. This project explores how far you can go by combining a lightweight GPU renderer with a native shell for a dramatically smaller footprint and near‑instant startup.

Result: lower memory pressure, near‑instant cold starts, smaller footprint, simple embedding, and much more.

🎯 Project Philosophy & Goals

Feature	Ultralight (This Project)	Electron / CEF
Performance	⚡ Up to 6× faster in simple page render ops	Chromium baseline CEF
Memory Usage	🧠 ~1/10 RAM (no multi-process sandbox)	High (multi-process JS + GPU + Extensions)
Startup	🚀 < 1s typical	3–5s cold start
Disk Footprint	📦 ~30–50 MB packaged	1+ GB (runtime + Cache)
Rendering	🎨 Lightweight GPU	Full Chromium CEF Stack
Architecture	🧱 Native C++ + pixel buffer compositing	Node.js + Chromium + Interop Bridge

Goals:

Showcase minimal native browser shell design.
Provide reference for Ultralight SDK Browser.
Preliminary lightweight content / ad-block / tracking-block.
Highlight performance vs conventional heavy frameworks.

🖥️ Supported Platforms & Architectures

Platform	Architectures	CI Artifacts	Notes
Windows 10/11+	x64	Portable ZIP, optional NSIS installer	ARM64 SDK not yet published by Ultralight
macOS 12+	x64, arm64	TGZ, optional DMG	ARM64 auto‑detected when runner host is ARM64
Linux (Ubuntu/Fedora etc.)	x64, arm64	TGZ / DEB / RPM	ARM64 requires aarch64 runner; workflow automatically includes detection & fallback

ARM64 archives are probed automatically when available in the base-sdk branch (eg: ultralight-free-sdk-<ver>-linux-arm64.7z, ...-mac-arm64.7z). Current public CI uses x64 runners; arm64 builds may require:

Self‑hosted runner (Apple Silicon / aarch64 Linux)
Future strategy matrix addition (see CI section)

📥 Get the App

Official tagged releases: 🎉 Ultralight Web → Browser Releases Page

Development (continuous) artifacts (latest successful dev workflow runs):

Platform	Architectures	Packages	Latest Runs
Linux	x64, arm64*	TGZ, DEB, RPM	Open runs
macOS	x64, arm64	TGZ, DMG	Open runs
Windows	x64	ZIP (portable) / optional Installer	Open runs

Notes:

✅ Linux AMD64 artifacts appear when an x64 runner is used or when ULTRALIGHT_SDK_URL points to an AMD64 SDK.
✅ Linux ARM64 artifacts appear when an aarch64 runner is used or when ULTRALIGHT_SDK_URL points to an arm64 SDK.
✅ Windows AMD64 artifacts appear when an aarch64 runner is used or when ULTRALIGHT_SDK_URL points to an arm64 SDK.
✅ macOS ARM64 artifacts are produced automatically when the CI runner is Apple Silicon.
✅ macOS AMD64 artifacts appear when an x64 runner is used or when ULTRALIGHT_SDK_URL points to an AMD64 SDK.
🕒 Windows ARM64 artifacts are not yet published by Ultralight [SOON™].

How to fetch artifacts:

Open the workflow link for your platform/arch.
Click the latest green run (success).
Scroll to “Artifacts” (bottom) and download the desired archive.

📥 Installation

🟦 Windows

Installer:

Download Ultralight-WebBrowser-Installer.exe from Releases
Install it and get happy!

Portable:

Download c from Releases
Extract to any folder
Run Ultralight-WebBrowser.exe

Optional: Use the NSIS installer (*-Windows-Installer.exe) if available.

🍎 macOS

TGZ Archive:

tar -xzf Ultralight-WebBrowser-*.tar.gz
./Ultralight-WebBrowser

DMG Image:

Mount the DMG
Drag to Applications
Right-click → Open (first launch, to bypass Gatekeeper)

🐧 Linux

Debian/Ubuntu (DEB):

sudo apt install ./Ultralight-WebBrowser-*.deb
ultralight-webbrowser

Fedora/RHEL (RPM):

sudo dnf install ./Ultralight-WebBrowser-*.rpm
ultralight-webbrowser

Portable (TGZ):

tar -xzf Ultralight-WebBrowser-*.tar.gz -C ~/.local/opt
~/.local/opt/UltralightWebBrowser/Ultralight-WebBrowser

✨ Features

Core Browser Functionality

GPU‑Accelerated Rendering – Powered by Ultralight core engine
Low Memory Footprint – Single process shell architecture (~1/10 RAM vs. Electron)
HTML5 / CSS3 / Modern JS Support – Full web standards compliance
Multi‑Tab Interface – Chrome-style draggable tabs with smooth animations
Navigation Controls – Back / Forward / Reload / Stop / Address bar
Dynamic Page Indicators – Real-time title updates and loading states
Responsive Resize – Fluid layout adaptation

Privacy & Security

Lightweight Ad & Tracker Filtering
- Domain + substring + glob pattern matching
- Rule sources: assets/blocklist.txt + all .txt in assets/filters/
- Formats: example.com, 0.0.0.0 example.com, ||example.com^, /ads.js, *://*/*analytics*.js
- Always allowed: file://, data:
- Toggle via toolbar icon or Settings
- Requires SDK network interception capabilities
Location Spoofing – Override geolocation with custom coordinates
- Configurable latitude/longitude values
- Preset city buttons (New York, London, Tokyo, Sydney, Paris)
- Per-site geolocation override via JavaScript injection
Do Not Track (DNT) – Configurable header setting
Clear History on Exit – Optional automatic cleanup
Web Security Controls – JavaScript, cookies, storage permissions

User Interface & Experience

Modern Glassmorphic Design – Semi-transparent overlays with backdrop blur
Dark Mode – Global theme toggle with persistent preferences
Compact Tabs Mode – Space-saving layout (60px UI height, 12em tab width)
Toolbar Icons – Quick access to Inspector, Downloads, AdBlock, Menu
Bookmark System – Save favorite sites with toolbar star icon and bookmarks bar
Bookmark Manager – Organize bookmarks with folder support and quick access
Download Manager – Full-featured UI with progress tracking and notifications
- WebP to PNG conversion – Automatic conversion of downloaded WebP images
- Configurable download location prompts
- Download history and status tracking
Settings Panel – Comprehensive configuration across 7+ categories:
- Appearance (Dark Mode, Vibrant Window, Transparent Toolbar, Compact Tabs)
- Privacy & Security (AdBlock, Trackers, JavaScript, Web Security, Cookies, DNT, History, Location Spoofing)
- Address Bar & Suggestions (Autocompletion, Favicons)
- Downloads (Badge, Auto-open Panel, Ask Location, WebP to PNG Conversion)
- Performance (Smooth Scrolling, Hardware Acceleration, Local Storage, Database)
- Accessibility (Reduce Motion, High Contrast, Caret Browsing)
- Developer (Remote Inspector, Performance Overlay)
- DRM Content (DRM WebView toggle for protected content)
Settings Search – Quick search to find specific settings
Auto-Save Settings – Automatic persistence of preference changes
Custom User Agent – Configurable browser identification string
Persistent Settings – JSON-based storage with runtime updates
Context Menu – Right-click actions and shortcuts
Keyboard Shortcuts – Customizable shortcut mapping system
Favicon Support – Site icons in tabs and suggestions
Autosuggestion – Intelligent URL/search completions with popular sites

DRM Content Support (Experimental)

DRM WebView Subsystem – Platform-native WebView for DRM-protected content
- Windows: WebView2 (Edge/Chromium) integration
- macOS: Native WKWebView with Cocoa/WebKit frameworks
- Linux: WebKit2GTK integration
Automatic Fallback – Seamless switching between Ultralight and native WebView
DRM Status Indicators – Visual feedback for DRM content detection
Per-Platform Optimization – Native framework integration for best performance

Developer Features

JavaScript ↔ Native Bridge – window.__ul API for deep integration
Local History API – In-memory browsing history (non-persistent by default)
Shortcut Mapping – JSON-based keyboard shortcut configuration
Debug Panel – Runtime settings inspection and diagnostics

🆕 Recent Updates

v0.9.6 (In Development)

New Features

Location Spoofing – Override browser geolocation with custom coordinates
- Configurable latitude/longitude in Settings → Privacy
- Preset city buttons: New York, London, Tokyo, Sydney, Paris
- JavaScript geolocation API override for privacy protection
WebP to PNG Conversion – Automatic conversion of downloaded WebP images
- Windows Imaging Component (WIC) based conversion
- Toggle in Settings → Downloads
- Preserves original filename with PNG extension
Session Restore – Restore tabs and state from previous browsing session
Password Manager – Secure credential storage and autofill

Improvements

Enhanced download manager with format conversion support
Expanded settings catalog (30+ options)
Improved privacy controls with geolocation override

v0.9.5 (Previous Release)

Major Features

Dark Mode – Global theme toggle with persistent preferences
Settings Panel – 26+ configurable options across 7 categories
Download Manager – Full-featured UI with progress tracking
ARM64 Support – Native builds for Apple Silicon and ARM Linux
URL Suggestions – Intelligent autocompletion with popular sites
Quick Inspector – Built-in development tools
Keyboard Shortcuts – Customizable shortcut mapping system

Earlier Merged Features (dev → main)

PR #45: Implement Features from Dev into Main

Major feature sync bringing all development improvements to the stable branch.

PR #43: Fully Functional Compact Tabs

Dynamic compact tabs mode with live toggle
No restart required for layout changes
Improved tab reload and settings mutation handling

PR #42: Settings Auto-Save Functionality

Automatic saving of settings changes
Toggle option for auto-save behavior
Seamless preference persistence

PR #41: Custom User Agent Setting

Configurable browser User-Agent string
New UI handling for setting changes
Enhanced request customization

PR #40: Icons Bar Styles Fix

Fixed toolbar icon styles and transitions
Improved download icon behavior
Polished visual feedback

PR #39: General Project Optimization

NSIS path detection improvements
PowerShell environment variable fixes
Windows CI workflow enhancements

Current Development (feature/drm-subsystem-implementation)

DRM WebView Subsystem – Cross-platform native WebView integration
Bookmark System – Full bookmark management with toolbar integration
Settings Search – Quick-find functionality for settings panel
CI/CD Improvements – Full ARM64 support for Linux and macOS

🛠️ Tech Stack

Component	Technology
Renderer	Ultralight SDK
Language	C++17, Objective-C++ (macOS)
Window/Input	GLFW
Graphics	OpenGL 3.3
Build System	CMake + CPack
CI/CD	GitHub Actions (x64 + ARM64)
DRM (Windows)	WebView2 (Edge/Chromium)
DRM (macOS)	WKWebView (Cocoa/WebKit)
DRM (Linux)	WebKit2GTK

🗺️ Roadmap

✅ Complete

GPU-Accelerated Rendering
Multi-Tab Interface
Ad & Tracker Blocking
Download Manager
Settings Panel (30+ options)
Dark Mode & Themes
DRM WebView (all platforms)
ARM64 Support
Auto-Save Settings
Custom User Agent
Settings Search
Compact Tabs Mode
Location Spoofing
WebP to PNG Conversion
Session Restore
Password Manager
Extension/Plugin API
Persistent History

🚧 In Progress

Bookmark System + Import/Export
Directories Organization
Accessibility Enhancements
Performance Optimizations
Tab Groups

🔮 Planned

Multi-Profile Support (?)
Reader Mode
Screenshot Tool (?)
Custom Themes
Sync Service (?)
DRM Detection Improvements

🔧 Troubleshooting

Common Issues

Issue	Solution
Blank window	Verify OpenGL 3.3 support; check library files
Settings not loading	Check `setup/settings.json` exists and is valid JSON
AdBlock not working	Ensure SDK supports network interception
DRM not playing	Enable in Settings → DRM Content
DRM WebView crash (macOS)	Ensure Cocoa/WebKit frameworks available
DRM WebView crash (Linux)	Install `libwebkit2gtk-4.1-dev`
macOS Gatekeeper	Right-click → Open (first launch)
Bookmarks not saving	Check write permissions for storage directory

Debug Tips

Launch from terminal to see initialization logs
Enable Performance Overlay in Settings → Developer
Delete setup/settings.json to reset to defaults
Check assets/blocklist.txt for filter syntax errors
Verify SDK presence in data/ or ULTRALIGHT_SDK_ROOT

🔄 CI / Automation

Active Workflows

Workflow	Platform	Features
`build-all.yml`	All	Meta-workflow (main badge)
`build-windows.yml`	Windows x64	Optional NSIS installer
`build-macos.yml`	macOS x64	Cocoa/WebKit linking
`build-macos-arm64.yml`	macOS ARM64	Apple Silicon
`build-linux.yml`	Linux x64	GTK3, WebKit2GTK
`build-linux-arm64.yml`	Linux ARM64	Self-hosted/emulated

Environment Variables

Variable	Purpose
`ULTRALIGHT_SDK_URL`	Override auto-detected SDK URL
`ULTRALIGHT_VERSION`	Override SDK version
`WEBBROWSER_VERSION`	App version label
`PACKAGE_GENERATORS`	CPack generators (`TGZ;DEB;RPM`)
`CREATE_INSTALLER`	Build NSIS installer (Windows)

🔐 DRM WebView Notes

The DRM WebView subsystem provides native WebView integration for playing DRM-protected content (Netflix, Disney+, etc.) that cannot be rendered by the Ultralight engine.

How It Works

Detection: Browser detects DRM-protected content via content type or site rules
Fallback: Automatically switches from Ultralight to native WebView
Integration: Native WebView overlays the main window with proper z-ordering
Return: User can switch back to Ultralight for regular browsing

Platform Implementations

Platform	Native WebView	DRM Support	Notes
Windows	WebView2 (Edge/Chromium)	Widevine, PlayReady	Requires Edge runtime
macOS	WKWebView	FairPlay, Widevine	Native Cocoa/WebKit
Linux	WebKit2GTK	Limited	WebKit2GTK 4.1 preferred

Enabling DRM WebView

Open Settings → DRM Content
Toggle Enable DRM WebView
Navigate to DRM-protected content
Browser will automatically use native WebView when needed

Build Requirements

Windows: WebView2 SDK (auto-detected by CMake)
macOS: Xcode with Cocoa/WebKit frameworks
Linux: libwebkit2gtk-4.1-dev or libwebkit2gtk-4.0-dev

📚 Documentation

🧩 JavaScript Bridge API

The window.__ul API is injected into the main frame for native integration:

// Navigation
__ul.navigate("https://example.com");
__ul.newTab("https://example.org");
__ul.back(); __ul.forward(); __ul.reload();

// Settings
const settings = __ul.getSettingsSnapshot();
__ul.updateSetting("enable_adblock", true);
__ul.saveSettings();

// Theme
__ul.toggleDarkMode();
if (__ul.isDarkModeEnabled()) { /* ... */ }

// History
const history = __ul.getHistory();
__ul.clearHistory();

// App Info
const info = __ul.getAppInfo();
// { name: "Ultralight WebBrowser", version: "1.4.0" }

🔐 DRM WebView System

For DRM-protected content (Netflix, Disney+, etc.):

Platform	WebView	DRM Support
Windows	WebView2	Widevine, PlayReady
macOS	WKWebView	FairPlay, Widevine
Linux	WebKit2GTK	Limited

Enable: Settings → DRM Content → Enable DRM WebView

The DRM WebView subsystem provides native WebView integration for playing protected content that cannot be rendered by the Ultralight engine.

How It Works:

Browser detects DRM-protected content via content type or site rules
Automatically switches from Ultralight to native WebView
Native WebView overlays the main window with proper z-ordering
User can switch back to Ultralight for regular browsing

📍 Location Spoofing

Override the browser's geolocation API with custom coordinates for privacy protection.

Configuration:

Open Settings → Privacy & Security
Enable Location Spoofing
Enter custom Latitude and Longitude values
Or use preset city buttons: New York, London, Tokyo, Sydney, Paris

How It Works:

Overrides navigator.geolocation.getCurrentPosition()
Overrides navigator.geolocation.watchPosition()
Returns spoofed coordinates to all web pages
Does not affect actual device location

Preset Coordinates:

City	Latitude	Longitude
New York	40.7128	-74.0060
London	51.5074	-0.1278
Tokyo	35.6762	139.6503
Sydney	-33.8688	151.2093
Paris	48.8566	2.3522

🛡️ Ad Blocking

Rules loaded from:

assets/blocklist.txt
assets/filters/*.txt

Supported formats:

example.com
0.0.0.0 example.com
||example.com^
/ads.js
*://*/*analytics*.js

Always allowed: file://, data: URLs

Toggle via toolbar icon or Settings → Privacy → Enable AdBlock

⚙️ Settings Categories

Category	Options
Appearance	Dark Mode, Vibrant Window, Transparent Toolbar, Compact Tabs
Privacy & Security	AdBlock, Tracker Blocking, JavaScript, Cookies, DNT, Clear History, Location Spoofing
Address Bar	Autocompletion, Favicons, Suggestions
Downloads	Badge, Auto-open Panel, Location Prompt, WebP to PNG Conversion
Performance	Smooth Scrolling, Hardware Acceleration, Local Storage
Accessibility	Reduce Motion, High Contrast, Caret Browsing
Developer	Remote Inspector, Performance Overlay
DRM Content	Enable DRM WebView

⌨️ Keyboard Shortcuts

Shortcuts are customizable via assets/shortcuts.json:

Action	Default Shortcut
New Tab	`Ctrl+T`
Close Tab	`Ctrl+W`
Reload	`Ctrl+R` / `F5`
Back	`Alt+Left`
Forward	`Alt+Right`
Address Bar	`Ctrl+L`
Find	`Ctrl+F`
Settings	`Ctrl+,`
Developer Tools	`F12`

🔄 CI / Automation

Active Workflows

Workflow	Platform	Features
`build-all.yml`	All	Meta-workflow (main badge)
`build-windows.yml`	Windows x64	Optional NSIS installer
`build-macos.yml`	macOS x64	Cocoa/WebKit linking
`build-macos-arm64.yml`	macOS ARM64	Apple Silicon
`build-linux.yml`	Linux x64	GTK3, WebKit2GTK
`build-linux-arm64.yml`	Linux ARM64	Self-hosted/emulated

Environment Variables

Variable	Purpose
`ULTRALIGHT_SDK_URL`	Override auto-detected SDK URL
`ULTRALIGHT_VERSION`	Override SDK version
`WEBBROWSER_VERSION`	App version label
`PACKAGE_GENERATORS`	CPack generators (`TGZ;DEB;RPM`)
`CREATE_INSTALLER`	Build NSIS installer (Windows)

🛠️ Tech Stack

Component	Technology
Renderer	Ultralight SDK
Language	C++17, Objective-C++ (macOS)
Window/Input	GLFW
Graphics	OpenGL 3.3
Build System	CMake + CPack
CI/CD	GitHub Actions (x64 + ARM64)
DRM (Windows)	WebView2 (Edge/Chromium)
DRM (macOS)	WKWebView (Cocoa/WebKit)
DRM (Linux)	WebKit2GTK

🤝 Contributing

Fork the repository
Create feature branch: git checkout -b feature/amazing-feature
Commit changes: git commit -m "Add amazing feature"
Push: git push origin feature/amazing-feature
Open a Pull Request

Guidelines:

Keep PRs focused and small
Include performance notes if relevant
Add tests for core logic changes
Follow existing code style

🔒 Security & Privacy

This project:

Does NOT implement hardened sandboxing found in mainstream browsers
Stores only ephemeral in-memory history (no disk persistence by default)
Performs lightweight filtering—no advanced tracker heuristics
Should not be used for security-critical tasks without further auditing

📄 License

MIT License — see LICENSE for details.

🙏 Acknowledgements

Ultralight — Lightweight HTML renderer
GLFW — Cross-platform windowing
Open-source community contributors

_{⚠️ Disclaimer: This is an educational project demonstrating minimal browser architecture.
Not recommended for security-critical tasks without additional hardening.}

Made with ❤️ for Ultralight SDK by @ovsky

Name		Name	Last commit message	Last commit date
Latest commit History 484 Commits
.github/workflows		.github/workflows
.vscode		.vscode
_CPack_Packages/win64/ZIP		_CPack_Packages/win64/ZIP
assets		assets
cmake		cmake
data		data
docs		docs
libs		libs
scripts		scripts
setup		setup
src		src
tests		tests
.gitattributes		.gitattributes
.gitignore		.gitignore
.yamllint.yml		.yamllint.yml
CMakeLists.txt		CMakeLists.txt
LICENSE		LICENSE
README.md		README.md
browser.ico		browser.ico
browser.rc		browser.rc
compilation_complete.ps1		compilation_complete.ps1
compilation_fastbuild.ps1		compilation_fastbuild.ps1
compilation_justcompile.ps1		compilation_justcompile.ps1
compilation_run.ps1		compilation_run.ps1
favicon.webp		favicon.webp
logo.png		logo.png
logo.svg		logo.svg
resource.h.bak		resource.h.bak

License

ovsky/Ultralight-WebBrowser

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Ultralight Web Browser ✨

🧭 Table of Contents

🚀 Why Ultralight? Ditch the Bloat

🎯 Project Philosophy & Goals

🖥️ Supported Platforms & Architectures

📥 Get the App

📥 Installation

✨ Features

Core Browser Functionality

Privacy & Security

User Interface & Experience

DRM Content Support (Experimental)

Developer Features

🆕 Recent Updates

v0.9.6 (In Development)

New Features

Improvements

v0.9.5 (Previous Release)

Major Features

Earlier Merged Features (dev → main)

PR #45: Implement Features from Dev into Main

PR #43: Fully Functional Compact Tabs

PR #42: Settings Auto-Save Functionality

PR #41: Custom User Agent Setting

PR #40: Icons Bar Styles Fix

PR #39: General Project Optimization

Current Development (feature/drm-subsystem-implementation)

🛠️ Tech Stack

🗺️ Roadmap

✅ Complete

🚧 In Progress

🔮 Planned

🔧 Troubleshooting

🔄 CI / Automation

Active Workflows

Environment Variables

🔐 DRM WebView Notes

How It Works

Platform Implementations

Enabling DRM WebView

Build Requirements

📚 Documentation

🔄 CI / Automation

Active Workflows

Environment Variables

🛠️ Tech Stack

🤝 Contributing

🔒 Security & Privacy

📄 License

🙏 Acknowledgements

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