Online JS code compression tool - Quickly compress JavaScript code

This online JS code compression tool is built on open-source Terser technology, fully supporting ES6+ syntax and modularity. It provides one-click JavaScript code compression, aiming to improve web page loading speed and front-end performance by reducing JS file size and resource transfer. (It's suitable for optimizing page performance, static resource size, and fast online verification.)

Inspiration

To address the common launch challenges developers face, such as large JavaScript file sizes, slow page load times, and initial rendering issues, we've designed an online JS compression tool that doesn't require local builds. Users can directly paste their code and compress it with one click, quickly generating slimmed-down JS files for production or testing. This simplifies front-end performance optimization and reduces bandwidth costs.

Instructions

1. Paste the JavaScript code to be compressed into the input box above.

2. Click "Compress Code."

3. Copy the compressed code to the project source file with one click.

Application Scenarios

• Quickly compress a single JS file before going live to reduce size and increase page loading speed.

• Performs online minification verification on single-page applications or modular scripts to evaluate compression effectiveness.

• This function can be used as a temporary front-end performance optimization measure when local build tools cannot be run immediately.

Implementation Principle

The tool calls Terser.minify(code): parses the source code to generate an abstract syntax tree (AST), performs standard compression and identifier renaming optimizations, and outputs functionally equivalent but smaller JavaScript code, thereby reducing transmission size and speeding up browser loading and parsing.

FQA

1. Does it support ES6+?

   Yes, this tool is based on Terser and can handle ES6/ES2015 and above syntax and modular writing.

2. Does minification change the functionality of the code?

   Typically not—minification only optimizes the code size at the syntactic level. However, if your code relies on runtime string eval, dynamic constructors, or unreferenced global names, issues may occur. Please verify in a test environment before going live.

3. How much size and loading time can be saved?

   The saving percentage depends on the original code structure and whether it has been compressed. A typical size reduction is 20%-70%. The actual speedup effect depends on factors such as network conditions and caching strategies.

4. How to deploy after compression?

   Back up the uncompressed source code, replace the online static resources with the compressed files, and perform regression verification in a test environment. Only release the code after confirming that it works correctly.

5. How is this different from code obfuscation/encryption tools?

   Minification focuses on optimizing file size and loading performance, and may include simple identifier renaming. Obfuscation/encryption focuses on increasing readability and improving source code protection. The two can be combined as needed.