DevToolbox

Package.json Generator

Generate package.json files visually with form fields, validation, template presets, and live JSON preview.

About This Tool

The Package.json Generator is a free browser-based tool that helps developers create package.json files through a visual form instead of editing raw JSON by hand. Whether you are bootstrapping a new npm package, setting up a monorepo, or converting an existing project, this tool generates a correctly structured manifest in seconds.

The package.json file is the heart of every Node.js project. It tells npm (or yarn, pnpm) which dependencies to install, which scripts to run, where to find entry points, and what metadata to publish to the registry. Getting the structure right from the start avoids headaches down the road, especially for fields like exports, engines, and files that have specific formatting requirements.

All processing happens entirely in your browser. No data is sent to any server, making this tool safe for any project. The form validates package names against npm's naming rules (lowercase, no spaces, scoped names supported) and checks version numbers for valid semver format in real time.

Five template presets are included to help you get started quickly: Node.js CLI, React App, Express API, TypeScript Library, and Monorepo Root. Each preset populates common scripts, dependencies, and configuration fields appropriate for that project type. You can customize every field after applying a preset.

How to Use

  1. Optionally select a template preset (Node.js CLI, React App, Express API, TypeScript Library, or Monorepo Root) to populate common fields.
  2. Fill in basic information: package name (required), version (required, semver), description, author, license, and whether the package is private.
  3. Expand the Entry Points section to set main, module, types, and exports fields.
  4. Add scripts using the quick-add preset buttons (start, dev, build, test, lint) or create custom key-value pairs.
  5. Add dependencies, devDependencies, and peerDependencies with package names and version ranges.
  6. Expand Advanced to configure repository, bugs, homepage, engine constraints, and the files array.
  7. Review the live JSON preview on the right, then Copy or Download the file. Use Ctrl+Shift+C to copy with a keyboard shortcut.

FAQ

What is a package.json file?

A package.json file is the manifest of a Node.js project. It describes the project's name, version, dependencies, scripts, entry points, and other metadata. npm, yarn, and pnpm all use this file to install dependencies and run scripts.

Is my data safe with this tool?

Yes. The entire tool runs client-side in your browser. No data is sent to any server. Your package configuration never leaves your machine.

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