Question 1

How do I unminify JavaScript?

Accepted Answer

Paste the minified code and click Format. Prettier reparses it and prints it with proper line breaks, indentation and spacing. Variable names that a minifier shortened (a, b, t) cannot be recovered — no tool can — but the structure becomes readable enough to debug or audit.

Question 2

Which syntax is supported?

Accepted Answer

Everything Prettier’s Babel parser understands: ES modules, async/await, classes, optional chaining, private fields, top-level await, JSX and the latest ECMAScript proposals that have shipped in browsers. TypeScript type annotations are not parsed here — strip them or use a TypeScript formatter.

Question 3

Why does the output look different from my editor’s Prettier?

Accepted Answer

Options. This tool uses a 100-character print width and lets you set indentation, semicolons and quote style; a project’s .prettierrc may differ (80 columns, trailing commas “all”, etc.). The logic is the same Prettier release, so aligning the options gives identical output.

Question 4

Does formatting change how the code runs?

Accepted Answer

No. Prettier only changes whitespace, line breaks, quotes and optional semicolons; the abstract syntax tree is identical before and after. If the input has a syntax error the formatter refuses and reports the line and column instead.

Question 5

Is my code uploaded?

Accepted Answer

No. Prettier’s standalone build runs entirely in your browser, so proprietary scripts stay on your machine.

JavaScript Formatter

Prettier defaults used here

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