📱 HTMLOpen — Immersive Fullscreen HTML & WebApp Runner for Android

A lightweight, zero-bloat Android application that lets you run any local .html file, offline web app, or HTML5 game as a native, full-screen standalone application.

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📸 Preview

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💡 The Problem with Standard Mobile Browsers

When trying to play offline HTML5 games (Construct 3, Phaser, Godot, RPG Maker, canvas games) or run local web dashboards on Android, regular browsers like Chrome or Firefox create massive friction:

1. Screen Clutter: Address bars, tab switchers, and system navigation bars permanently eat screen real estate.
2. CORS / file:// Restrictions: Modern browsers block multi-file offline web projects from loading sibling scripts, images, audio, or JSON files.
3. Audio Gestures Required: Web audio often refuses to play without manual tap interactions.
4. Heavy Overhead: Modern browsers consume hundreds of megabytes of RAM just to render a simple offline tool.

HTMLOpen solves this completely: It wraps Android's native hardware-accelerated WebView into a 445 KB standalone container with unrestricted local file access and true sticky immersive mode.

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✨ Features

• 🎮 True Sticky Immersive Fullscreen: Automatically hides the Android status bar and navigation bar (SYSTEM_UI_FLAG_IMMERSIVE_STICKY). Swipe gestures won't disrupt full-screen gaming.
• 🔓 Universal Local File & Asset Loading: Configured with setAllowUniversalAccessFromFileURLs(true) so HTML files can seamlessly load external CSS, JavaScript, textures, WebAssembly (.wasm), and JSON data files from storage.
• ⚡ Ultra Lightweight (< 500 KB): Pure native Java with zero third-party dependencies, zero tracking, zero background telemetry, and zero ads.
• 🚀 Hardware Acceleration & Large Heap: Fully hardware-accelerated rendering with largeHeap="true" for smooth 60fps WebGL/Canvas graphics.
• 📂 Intent File Association: Automatically registers as a handler for .html and .htm files. Tap any HTML file in Files, Solid Explorer, or ZArchiver and choose Open with HTMLOpen.
• 🔊 Auto Audio Playback: Configured with mediaPlaybackRequiresUserGesture(false) so game audio and sound effects start immediately.
• 💾 Full Web Storage: LocalStorage, IndexedDB, and DOM Storage are fully enabled and persist across app sessions.

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📥 Download APK

Get the latest pre-compiled, signed APK ready to install:

👉 Download HTMLOpen.apk (v1.0.0) (~445 KB)

Installation Instructions:

1. Download HTMLOpen.apk to your Android device.
2. Open the file and tap Install (Enable "Install Unknown Apps" for your browser/file manager if prompted).
3. Launch HTMLOpen and tap Choose .HTML File, or tap any .html file from your device storage and select HTMLOpen.

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🛠️ Typical Use Cases

• Offline Mobile Gaming: Play HTML5 games, retro WebAssembly emulators, or fan-made web ports in full landscape without browser UI.
• Smart Home & Tablet Dashboards: Wall-mount a low-cost Android tablet running a Home Assistant or custom HTML/CSS dashboard in distraction-free kiosk mode.
• Digital Signage & Kiosks: Display interactive HTML menus, schedules, or slideshows with full screen lockdown.
• Local Web Development & Testing: Quickly preview web layouts, PWAs, or canvas projects directly from your phone's storage.

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💻 Building from Source

Prerequisites

• Android Studio (Koala / Ladybug or newer) or Android SDK command-line tools.
• JDK 17+

Build Commands:

# Clone the repository
git clone https://github.com/Gilzone/html-open.git
cd html-open

# Build debug APK
./gradlew assembleDebug

# Build release APK
./gradlew assembleRelease

The compiled APK will be located at app/build/outputs/apk/release/app-release.apk.

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📜 License

This project is open-source under the MIT License.