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圧縮 JavaScript Quickly Without a Bundler
Every byte matters when shipping JavaScript to users. Comments, whitespace, and extra フォーマットting add file size. Bundlers like Webpack and esbuild handle minification automatically, but sometimes you need quick, lightweight minification: removing comments from scripts you're embedding inline, reducing code snippets for documentation, or 圧縮ing scripts before shipping.
This JS Minifier strips comments and unnecessary whitespace, 圧縮ing JavaScript to the smallest readable フォーマット. It's not a full AST-level optimizer like Terser, but it's perfect for quick minification without heavyweight tooling.
What Gets Removed
Comments: Single-line (//) and multi-line (/* */) comments are stripped completely. License comments (often preserved by tools like Terser) are removed here, so if you need copyright headers, add them back post-minification or use a different tool.
Whitespace: Extra spaces, tabs, and newlines collapse. Line breaks only appear where JavaScript syntax requires them (after statements ending with semicolons).
フォーマットting: Code compacts to minimal space while remaining executable. This is different from code optimization—it doesn't rename variables or remove dead code. The resulting script is functionally identical.
圧縮ion Metrics
The tool shows you exactly how much you saved: bytes reduced and percentage 圧縮ion. For a 5KB script with lots of comments and indentation, you might see 30-40% reduction.
When to Use This vs. a Bundler
Use This Tool When:
- You need quick minification without build setup
- You're 圧縮ing small utility scripts
- You're reducing code snippets for documentation or inline embedding
- You want to see immediate minification results
- You're working with simple scripts that don't need advanced optimization
Use a Bundler When:
- You're shipping production code that needs AST-level optimization
- You need variable renaming, dead code elimination, and advanced 変換s
- You want scope analysis and aggressive optimizations
- You're bundling multiple files with dependencies
Real-World 使用例
Inline Scripts: Minify small JavaScript snippets you're embedding in HTML documents or templates.
Third-Party Script Distribution: If you're publishing JS for other developers to use, minify it before release to reduce payload size.
Userscripts & Bookmarklets: 圧縮 JavaScript you're publishing on Gist or other platforms where smaller size helps with sharing.
Documentation Code Examples: Reduce code snippets in docs to fit better in display areas.
Quick Testing: Rapidly check how much minification would save before committing to a full build process.
Limitations to Know
This tool uses regex-based text 変換ation, not AST parsing. It won't:
- Rename variables to shorter names
- Eliminate unused code
- Optimize control flow
- Inline small functions
For production code needing these optimizations, use Terser, esbuild, or similar tools as part of your build pipeline.
Copy & Embed Immediately
Once minified, copy with one click. Paste directly into your templates, inline scripts, or distribution packages.
100% ブラウザ-Based
Minification happens locally in your ブラウザ. Your code never touches a server, so you can minify proprietary or sensitive scripts safely.