Que fait JavaScript Formatter and Minifier ?
JavaScript Formatter and Minifier permet de formater et valider des données dans le navigateur et présente clairement le résultat et ses limites. Fonctions vérifiées : Prettier JavaScript formatting, Terser compression and mangling, Script and ES module modes, Local JavaScript download.
Formatting and minification target different artifacts
Use Prettier output for review, debugging, and source control. Use Terser output only as a tested deployment artifact. Neither mode executes the pasted program, bundles imports, resolves dependencies, or validates runtime behavior.
Comment l’utiliser ?
- Choose Format JavaScript for readable source or Minify JavaScript for a smaller delivery artifact.
- Select Script for classic browser or Node.js source, or ES module when the code uses import and export syntax.
- Paste JavaScript no larger than 2 MB, run the operation, then review and download javascript-output.js.
Exemple réel d’entrée et de sortie
Format and minify a small lookup function
Entrée
const tools=["HTML","JavaScript"];function findTool(name){return tools.find((tool)=>tool===name)??null}Sortie
const tools = ['HTML', 'JavaScript'];
function findTool(name) {
return tools.find((tool) => tool === name) ?? null;
}
Minified: const tools=["HTML","JavaScript"];function findTool(o){return tools.find(l=>l===o)??null}Prettier normalizes layout while preserving readable names. Terser removes optional syntax and can shorten local identifiers without executing the source.
Erreurs fréquentes et corrections
| Symptôme | Cause probable | Correction |
|---|---|---|
| Formatting or minification reports an unexpected token. | The source is incomplete, contains unsupported proposal syntax, or is TypeScript rather than JavaScript. | Correct the first syntax error and remove TypeScript-only annotations; this tool intentionally targets JavaScript and JSX parsed by Babel. |
| An import or export statement fails during minification. | The source type is set to Script even though the input is an ES module. | Select ES module before minifying source that contains import, export, or module-level semantics. |
| Minified code behaves differently in the application. | The code depends on function names, Function.prototype.toString(), stack formatting, top-level globals, or nonstandard side effects that conflict with optimizer assumptions. | Keep readable source under version control, test the minified artifact in the target runtime, and disable minification for incompatible code. |
Important behavior of JavaScript Formatter
Limite propre à cet outil : Minification can change function and variable names, remove unused code, and expose assumptions about reflection or side effects; regression-test the generated artifact before deployment.
Normes et références d’implémentation
- Prettier browser documentation (opens in a new tab)Documents standalone browser formatting and the Babel and ESTree plugins used for JavaScript.
- Terser API reference (opens in a new tab)Documents the asynchronous minify API, compression, mangling, module mode, and output options.
- ECMAScript language specification (opens in a new tab)Defines the JavaScript language syntax and semantics parsed by these tools.
JavaScript Formatter — FAQ
Does the JavaScript Formatter upload my input?
No. Processing runs in the current browser tab, and the page does not send tool input to a KitLumi processing endpoint.
What input does the JavaScript Formatter accept?
It accepts one JavaScript script or ES module up to 2 MB. The workspace checks the input and reports malformed or unsupported values before it produces a result.
What does the JavaScript Formatter produce?
It produces Prettier-formatted JavaScript or Terser-minified JavaScript. Copy and download controls appear when the output format supports them.
What limitation should I know?
Minification can change function and variable names, remove unused code, and expose assumptions about reflection or side effects; regression-test the generated artifact before deployment.
Quelles modifications ?
Mise à jour substantielle : JavaScript Formatter: Added Prettier JavaScript formatting, Terser compression and mangling, Script and ES module modes, Local JavaScript download, responsive controls, explicit runtime disclosure, and task-specific examples and limitations.