Name: JavaScript Formatter & Beautifier
Author: PureFormatter

Question 1

What does a JavaScript formatter do?

Accepted Answer

A JavaScript formatter parses your JavaScript source code and re-outputs it with consistent indentation, standardized spacing around operators, proper line breaks after statements, and organized bracket placement. JavaScript code written in a hurry, copy-pasted from Stack Overflow, or generated by a build tool is often messy and inconsistent. Formatting it makes the logic immediately clear — you can see loops, conditionals, function bodies, and object literals at a glance because they are all properly indented. PureFormatter uses a modern JS parser to produce high-quality, standard-compliant JavaScript output.

Question 2

Is my JavaScript code private when using PureFormatter?

Accepted Answer

Yes, completely. PureFormatter executes all formatting logic in your browser using client-side JavaScript. Your source code is never sent to any server, never logged, never stored, and never shared. This is critically important for professional developers who work with proprietary business logic, trade secrets, API integrations, or sensitive application code. You can use PureFormatter with full confidence on code that you cannot share with third parties. The tool works even when you're offline, further confirming that no network communication is involved.

Question 3

Does it support modern JavaScript (ES6+, ES2022)?

Accepted Answer

Yes. PureFormatter supports modern JavaScript syntax including arrow functions, template literals, destructuring assignment, spread and rest operators, async/await, optional chaining, nullish coalescing, class fields, private class methods, dynamic imports, and BigInt literals. We use a modern JavaScript parser that is kept up to date with the ECMAScript specification. If you encounter a modern JS feature that fails to format correctly, please report it — our goal is to fully support the current JavaScript language.

Question 4

Can I format TypeScript with the JavaScript formatter?

Accepted Answer

Basic TypeScript can often pass through the JavaScript formatter if the TypeScript-specific syntax is not too complex. However, for reliable TypeScript formatting, you should use a dedicated TypeScript formatter, as TypeScript introduces many additional syntax elements — type annotations, generics, decorators, enums, interfaces, and type assertions — that a pure JavaScript parser may not handle correctly. We are actively developing a dedicated TypeScript formatter tab that will be added to PureFormatter soon.

Question 5

Will formatting change the behavior of my JavaScript?

Accepted Answer

No, formatting changes only the visual presentation of your code — whitespace, indentation, and line breaks — never the logical meaning. The JavaScript engine ignores whitespace between tokens (with the exception of Automatic Semicolon Insertion edge cases). PureFormatter is careful to preserve the exact token sequence of your code, ensuring that the formatted output is semantically identical to the input. Your functions, variables, closures, and control flow all remain exactly the same after formatting.

Question 6

How do I minify JavaScript for production?

Accepted Answer

Click the Minify button to produce a compact, whitespace-free version of your JavaScript. Minification reduces file size by removing all unnecessary whitespace, comments, and line breaks. For serious production deployments, you should also consider using a full minifier like Terser or UglifyJS, which go further than whitespace removal — they rename variables to shorter names and apply dead-code elimination. PureFormatter's minification is a quick, lightweight option for fast results.

Question 7

Does PureFormatter handle JSX syntax?

Accepted Answer

JSX — the XML-like syntax extension used in React — is not supported by the current JavaScript formatter, which targets standard ECMAScript. Files with .jsx extension or containing JSX syntax will likely produce a parse error. Dedicated JSX support requires a different parser configuration. Adding JSX formatting is on our roadmap, as it is a popular request from React developers. In the meantime, using Prettier locally with the babel plugin configured is the most reliable option for JSX formatting.

Question 8

What is the best indentation style for JavaScript?

Accepted Answer

The JavaScript community is split between 2-space and 4-space indentation. Google's JavaScript Style Guide and Airbnb's popular style guide both recommend 2 spaces, while many legacy codebases and some communities prefer 4 spaces. PureFormatter defaults to 2 spaces, which is the most popular choice in modern JavaScript development. The best choice is the one your team already uses — configure PureFormatter to match your existing codebase conventions using the indent selector.

Question 9

Can I format multiple JavaScript files at once?

Accepted Answer

PureFormatter currently formats one file at a time. For batch formatting of multiple files, we recommend using Prettier — a command-line JavaScript formatter that can process entire directories with a single command such as prettier --write 'src/**/*.js'. Prettier supports the same formatting style as PureFormatter and can be integrated into your CI/CD pipeline, Git hooks, or IDE. Bulk formatting support is a feature we are considering for a future version of PureFormatter.

Question 10

Why do semicolons keep appearing after formatting?

Accepted Answer

PureFormatter follows the widely used style of adding semicolons at the end of statements. If your code uses ASI style — intentionally omitting semicolons — the formatter will add them back. Conversely, if you prefer no semicolons, you can remove them from the output before using it. We plan to add a semicolons toggle option to let you control this behavior. In team projects, adopting a consistent semicolon policy enforced via ESLint eliminates this ambiguity entirely.

JavaScript Formatter & Beautifier

What is a JavaScript Formatter & Beautifier?

How to Use PureFormatter

Frequently Asked Questions