Closure Compiler vs UglifyJS: What are the differences?

# Introduction
In web development, minifying JavaScript code is crucial for improving page load times and reducing file sizes. Closure Compiler and UglifyJS are two popular tools used for this purpose, each with its unique features and differences.

1. **Compilation Level**:
Closure Compiler offers advanced compilation levels (Simple, Advanced, and Whole Program) for optimizing code, while UglifyJS primarily focuses on minifying code without performing advanced optimizations.

2. **Code Structure**:
Closure Compiler rewrites and optimizes JavaScript code based on static program analysis, which can lead to tighter and more efficient code. In contrast, UglifyJS focuses on reducing code size by removing whitespace, renaming variables, and simplifying expressions.

3. **ES6 Support**:
Closure Compiler provides better support for modern JavaScript features such as ES6 and ES7 syntax by transpiling them to ES5 during the compilation process. UglifyJS, on the other hand, may struggle with handling advanced ES6 syntax and features.

4. **Error Reporting**:
Closure Compiler gives detailed error messages and warnings during compilation, helping developers identify and fix issues in their code. UglifyJS, while effective at minifying code, may not provide as informative error messages when issues arise.

5. **Community Support**:
Closure Compiler has a smaller but dedicated community that actively maintains and updates the tool, providing consistent support and improvements. UglifyJS, being more widely used, has a larger community but may have slower updates and fewer new features.

6. **Integration**:
Closure Compiler seamlessly integrates with other Google web development tools and workflows, making it a preferred choice for projects within the Google ecosystem. UglifyJS, being a standalone tool, can be easily integrated into various build processes and tools.

In Summary, Closure Compiler offers advanced compilation levels and enhanced error reporting, while UglifyJS focuses on code size reduction and ease of integration within different workflows.