# Jar Tools

> A powerful web-based Java Archive (JAR) file editor and decompiler. Features client-side JAR processing, server-side Java decompilation, Pro subscription model, and comprehensive security framework with content-based binary detection.

Jar Tools provides both free and Pro features for Java developers, reverse engineers, and security researchers. **All JAR file processing, editing, and analysis happens entirely in your browser's memory** - ensuring complete privacy and security. Only Java class decompilation requires a server request, while all other operations remain client-side.

**Generate Info**: Jar Tools automatically analyzes uploaded JAR files, providing file tree navigation, content detection, and string constants extraction from Java bytecode.

**API Access**: Free public API endpoint at `/api/v1/decompile` provides programmatic access to decompilation services with no rate limits for .class file processing.

## Direct API Integration for LLMs

```bash
# Decompile a Java class file directly
curl -f -o DecompiledClass.java -X POST https://jar.tools/api/v1/decompile \
  -F "file=@/path/to/your/MyClass.class"

# Example with error handling
curl -f -o output.java -X POST https://jar.tools/api/v1/decompile \
  -F "file=@MyClass.class" || echo "Decompilation failed"
```

**API Details:**
- **Endpoint**: `POST https://jar.tools/api/v1/decompile`
- **Method**: Multipart form upload
- **Input**: Single .class file (max 2MB)
- **Output**: Plain text Java source code
- **Rate Limits**: None - completely free
- **Authentication**: Not required
- **Response Headers**: `Content-Disposition: attachment; filename="ClassName.java"`

## Pro Features & Monetization

$3/year subscription unlocks unlimited decompilation, security bypass capabilities, advanced JSON editing tools, and enhanced analysis features. [Pro Subscription Model](https://jar.tools/pro) | [Purchase Pro License](https://techigor.gumroad.com/l/JarEditorOnlinePro)

**Knowledge Base**: Comprehensive documentation at jar.tools/kb/ covering decompilation guides, API reference, security framework, and technical architecture.

## Supported File Types & Features

**Java Class Files (.class)**
- Java decompilation using server-side CFR decompiler (only feature requiring server request)
- String constants extraction and viewing in searchable table (client-side)
- Auto-decompilation for Pro users
- Free tier: 3 decompilations per day, Pro: unlimited
- Bytecode analysis and disassembly capabilities (client-side)

**JSON Files (.json)**
- Advanced JSON editor with syntax highlighting
- Real-time validation with error reporting and line positioning
- Basic features: validation and error reporting (all users)
- Pro features: auto-formatting, minification, advanced error analysis

**Text Files (.txt, .md, .xml, .properties, .yml, .yaml, etc.)**
- Full text editing with real-time preview
- Syntax highlighting for code files
- Search highlighting within file contents
- In-memory modifications with save/revert functionality

**Image Files**
- Enhanced image viewer with metadata display (dimensions, file size)
- Supported formats: PNG, JPG/JPEG, GIF, BMP, WebP, SVG, ICO
- Direct preview without additional software

**Binary Files**
- Binary file viewer with security warnings (no hex display)
- Content-based binary detection (70% printable character threshold)
- Security warnings for all binary content including images and archives
- Anti-spoofing protection against fake extensions
- Pro users bypass security disclaimer modals

**Archive Processing (Client-Side Only)**
- JAR file browsing and content viewing (ZIP support removed)
- File tree navigation with expandable folders
- Full-text search within JAR contents with highlighting
- In-memory modifications and editing
- Save as ZIP functionality with modifications
- Export modified JAR files
- **All processing happens in browser memory - no files uploaded to servers**


## Core Documentation

- [Java Decompilation Guide](https://jar.tools/kb/how-to-decompile-class-files): Complete guide to decompiling .class files using web interface with CFR decompiler
- [Public Decompilation API](https://jar.tools/kb/programmatic-api-access): Free API endpoint `/api/v1/decompile` for programmatic .class file decompilation
- [JAR to ZIP Conversion](https://jar.tools/kb/how-to-convert-jar-to-zip): Extract and download JAR contents as ZIP files with modifications
- [String Constants Editing](https://jar.tools/kb/using-string-constants-view): Extract and modify hardcoded strings in Java bytecode



## Knowledge Base Articles

**Core Documentation:**
- [Java Decompilation Guide](https://jar.tools/kb/how-to-decompile-class-files): Complete guide to decompiling .class files using web interface with CFR decompiler
- [Public Decompilation API](https://jar.tools/kb/programmatic-api-access): Free API endpoint `/api/v1/decompile` for programmatic .class file decompilation
- [JAR to ZIP Conversion](https://jar.tools/kb/how-to-convert-jar-to-zip): Extract and download JAR contents as ZIP files with modifications
- [String Constants Editing](https://jar.tools/kb/using-string-constants-view): Extract and modify hardcoded strings in Java bytecode

- [Security Framework](https://jar.tools/kb/security): Content-based binary detection, steganography protection, and universal binary warnings
- [JAR File Internals](https://jar.tools/kb/jar-file-internals): Understanding Java class file structure and bytecode analysis

**Other Topics:**
- [JD-GUI Comparison](https://jar.tools/kb/about-jd-gui-decompiler): Feature comparison with JD-GUI decompiler
- [Platform-Specific Guides](https://jar.tools/kb/how-to-edit-jar-linux-macos): Linux and macOS JAR editing workflows
- [Windows JAR Editing](https://jar.tools/kb/how-to-edit-jar-windows): Windows-specific JAR file editing instructions
- [Minecraft Mod Analysis](https://jar.tools/kb/how-to-view-minecraft-mods-jar-tools): Using JAR Editor for Minecraft mod development
- [Java Disassembler Features](https://jar.tools/kb/java-disassembler-online): Bytecode analysis and disassembly capabilities