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About this TypeScript Formatter Online TypeScript / TSX Formatter

Paste your TypeScript or TSX component, click **Format**, and get perfectly styled code powered by Prettier. This tool matches modern TypeScript syntax, supports .ts, .tsx, .mts, and .cts files, and is perfect for polishing snippets before sharing, debugging, or committing to your repo.

Key Features of This TypeScript Formatter

  • **Prettier-based formatting** for modern TypeScript and TSX (React) code
  • Normalizes spacing, indentation, semicolons, and brackets for a consistent style
  • Configurable **indent size (1–8)** and **spaces vs tabs** via UI controls
  • Adjustable **Wrap / Line Length** (`printWidth`) including a “no wrap” mode (very large printWidth)
  • File upload support for **.ts, .tsx, .mts, .cts** up to ~5 MB
  • Great for React + TypeScript frontends, Node.js APIs, libraries, and shared type packages
  • Client-side Prettier execution by default with **secure server fallback** if required plugins/parsers are missing
  • Perfect for quickly cleaning up snippets before sharing, debugging, posting in issues, or committing

🔧 How to Format TypeScript & TSX Code Online for typescript-formatter

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1. Paste or Drop Your Code

Copy any TypeScript or TSX file — components, hooks, utilities, types, API handlers — and paste it into the editor, or drag & drop a `.ts`, `.tsx`, `.mts`, or `.cts` file into the dropzone.

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2. Tune Formatting Options

Use the **Indent Size** slider to select 1–8 spaces and switch **Indent Style** between spaces and tabs. Adjust **Wrap / Line Length** to match your project’s `printWidth` (e.g. 80 or 100 columns, or 0 for effectively no wrapping).

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3. Run the Formatter

Click **Format**. The formatter runs Prettier with a `babel-ts` parser and TypeScript/Babel/ESTree plugins. In most cases everything runs client-side; if a required parser is missing, the tool can fall back to a secure server formatter.

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4. Copy or Download the Result

Review the formatted code, then copy it back into your editor or download the updated file. Commit the result with confidence, knowing it matches a consistent Prettier-like style.

Technical Specifications

Formatting Engine & Language Support

This tool is powered by a Prettier-based engine with a TypeScript-aware parser (`babel-ts`) and related plugins. It is designed to be deterministic and idempotent, so running it multiple times produces identical code.

FeatureSupportNotes
Languages✅ TypeScript, TSXIdeal for React components, hooks, utility modules, and Node.js services.
File extensions✅ .ts, .tsx, .mts, .ctsMatches common TypeScript module variants and project layouts.
Parser hint✅ babel-tsTS-aware parser compatible with modern ECMAScript and TS syntax.
Plugins✅ typescript, babel, estreeConfigured via Prettier runtime with `prettier/plugins/typescript`, `prettier/plugins/babel`, and `prettier/plugins/estree`.
Experimental syntax⚠️ PartialVery new TS features may require the latest Prettier version or local configuration.
Idempotent output✅ YesRerunning the formatter on already formatted code yields the same result.
If you hit a parser or plugin error, try reducing the snippet to the minimal repro, or run the latest Prettier directly in your project environment where you control the version and configuration.

Limits, Performance & Timeouts

The logic is tuned for fast, safe formatting of single files and snippets without freezing the browser.

Input TypeApproximate LimitDetails
Plain text input~2 MB (~2,000,000 characters)Hard limit enforced inside the formatter logic for stability.
Uploaded TS/TSX file~5 MBBounded by the UI `maxFileSize` constraint.
Formatting time< 1–2 s (typical)Depends on code size, browser engine, CPU, and device.
Timeout protection✅ Enabled (~25 s)The formatter aborts long jobs via an internal timeout to prevent lockups.
For large codebases or bulk formatting of entire directories, prefer using Prettier’s CLI or your IDE integration instead of the browser tool.

Indentation, Line Length & Output Style

Control indentation and wrapping so that the output matches your project’s Prettier and EditorConfig settings.

SettingOptionsRecommended Use
Indent styleSpaces / TabsSpaces for most JS/TS projects; tabs if your team standardizes on them.
Indent size1–8 spaces2 spaces is common for modern JS/TS; 4 spaces if you prefer extra visual structure.
Wrap / line length0–120 columns0 disables wrapping (internally uses a very large `printWidth`).
Typical printWidth80 / 100 / 12080 for maximum compatibility, 100–120 for wide-screen codebases.
Align these settings with your `.prettierrc`, `editorconfig`, and ESLint rules so online formatting stays consistent with local commits and CI checks.

Command-Line Prettier for TypeScript

Use this online formatter for fast one-off cleanups, and run Prettier via CLI or editor integrations for entire projects.

Linux / 🍏 macOS

Format a single TypeScript file with Prettier

prettier --parser babel-ts --write src/example.ts

Formats the file in place using a TS-aware `babel-ts` parser.

Format an entire src directory

prettier "src/**/*.{ts,tsx,mts,cts}" --parser babel-ts --write

Recursively formats TypeScript and TSX files in the `src` folder.

Windows (PowerShell / cmd)

Prettier in a Windows project

npx prettier "src/**/*.{ts,tsx}" --parser babel-ts --write

Uses `npx` to run your local Prettier version with TypeScript support.

Add a `format` script to `package.json` (for example: "format": "prettier \"src/**/*.{ts,tsx}\" --write") and run it before commits or in CI for consistent TypeScript style.

Practical TypeScript Formatter Use Cases

API & Backend TypeScript

Clean up controllers, services, handlers, and type definitions before code review.

  • Normalize formatting of DTOs, request handlers, and middleware functions.
  • Make large type definitions and interfaces easier to diff and review.
  • Reformat reproduction snippets copied from logs or Stack Overflow into proper TS.
// Example: Express route handler in TypeScript
import type { Request, Response } from "express";

export async function getUser(req: Request, res: Response) {
  const id = Number(req.params.id);
  if (!Number.isFinite(id)) {
    return res.status(400).json({ error: "Invalid user id" });
  }
  // TODO: fetch and return user JSON
}

React + TypeScript Components

Keep React components, hooks, and context providers consistently formatted and easy to scan.

  • Reformat deeply nested JSX trees to visually reveal component structure and props.
  • Ensure hooks-based logic follows a clean, predictable style.
  • Prepare polished TSX examples for blog posts, slide decks, and docs.
// Example: React functional component in TSX
import type { FC } from "react";

interface ButtonProps {
  label: string;
  onClick?: () => void;
}

export const Button: FC<ButtonProps> = ({ label, onClick }) => {
  return (
    <button type="button" onClick={onClick}>
      {label}
    </button>
  );
};

Learning & Teaching TypeScript

Help students and junior devs understand idiomatic TypeScript and TSX formatting.

  • Show messy code and demonstrate how Prettier reflows it into a standard style.
  • Compare before/after formatting to explain imports, types, and generics.
  • Provide clean, ready-to-run snippets for exercises and workshops.
// Example: Simple typed function for teaching
function add(a: number, b: number): number {
  return a + b;
}

❓ Frequently Asked Questions

❓What does this TypeScript formatter do?

It formats TypeScript and TSX code using a Prettier-based engine. You paste or upload your code, choose indentation and line-length options, and the tool returns clean, consistent output that is ready to commit or share.

🧪Which languages and file types are supported?

The formatter is built for TypeScript and TSX. It supports `.ts`, `.tsx`, `.mts`, and `.cts` extensions, covering typical React frontends, Node.js backends, libraries, and modern module layouts.

📏Is there a size limit for TypeScript input?

Yes. For browser stability, plain text input is limited to around 2 MB (~2,000,000 characters) and uploaded files to about 5 MB. For larger projects or batch formatting, run Prettier directly in your editor or via CLI.

🔐Is my TypeScript code uploaded to a server?

By default, formatting happens client-side in your browser using Prettier. In rare cases where a required parser or plugin cannot be loaded, the tool falls back to a secure server-side formatter. Even then, your code is processed transiently to compute the result and is not stored permanently.

⚙️How can I match my project’s Prettier settings?

You can control indentation (spaces vs tabs), indent size, and approximate line length. For an exact match with your `.prettierrc` (including quotes, trailing commas, etc.), use this tool for quick checks and rely on your project’s Prettier configuration via CLI or IDE for final formatting.

🚫Why do I sometimes see parser or plugin errors?

These errors usually appear when the code uses very new or experimental syntax that the bundled Prettier version doesn’t support, or when a parser plugin is unavailable in the browser environment. If this happens, simplify the snippet or run Prettier locally with your own configuration and dependencies.

Pro Tips

Best Practice

Run your code through this formatter before pasting into pull requests, issues, Gists, or blog posts so readers focus on logic instead of formatting.

Performance Tip

Use a `pre-commit` or `lint-staged` hook to run Prettier on all TypeScript files automatically before every commit.

Best Practice

Combine this formatter with ESLint (typescript-eslint) to catch both stylistic issues and real bugs in your TypeScript code.

CI Tip

Add `prettier --check` to your CI pipeline so inconsistent formatting fails the build and is fixed before merging.

Additional Resources

Prettier — Opinionated Code Formatter
Documentation
TypeScript Handbook
Reference
TypeScript Cheatsheets for React
Reference
ESLint + Prettier Setup for TypeScript
Documentation

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