JSON to JavaScript Object

Convert JSON to JS object with JSON.parse and JSON.stringify examples.

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Overview

JSON grew directly from JavaScript: Douglas Crockford identified a subset of JavaScript's object literal syntax that could serve as a data exchange format and called it JavaScript Object Notation. Ironically, JSON and a JavaScript object are not the same thing. A JavaScript object can hold functions, circular references, `undefined` values, `Date` instances, `Map`, `Set`, `RegExp`, and `Symbol` — none of which exist in JSON. When a JavaScript object goes through `JSON.stringify`, functions and `undefined` are silently dropped, and `Date` instances become ISO 8601 strings with no warning.

`JSON.parse` and `JSON.stringify` are the two methods on JavaScript's built-in JSON object, available in every modern browser and in Node.js without any import. `JSON.parse` accepts a second argument called a `reviver`: a function that transforms keys and values during parsing, useful for converting date strings back into `Date` instances. `JSON.stringify` accepts a `replacer` (function or array of keys to include in the output) and a `space` argument (number of spaces or indentation string).

Never use `eval()` to parse JSON, even though it works technically. `eval` executes any JavaScript code inside the string, opening a serious security hole if the JSON comes from an untrusted source. Before `JSON.parse` existed (before ES5 in 2009), `eval` was the only available option, but today there is no justification for using it. Another trap is calling `JSON.stringify` on an object with circular references: the function throws a `TypeError` immediately.

This tool converts the JSON you paste into ready-to-use JavaScript code, with examples of `JSON.parse` for reading and `JSON.stringify` for serialization. The generated code is compatible with modern browsers (ES2015+) and Node.js. For deep cloning in modern environments, consider `structuredClone()` as an alternative to the `JSON.parse(JSON.stringify(obj))` pattern: it is semantically more correct and generally faster.

Technical deep dive

Common questions summarized

  • What is this tool for?: It runs fully in your browser: useful to validate, format, or convert data in everyday development.
  • Are my inputs sent to a server?: Processing happens locally with JavaScript. We do not store what you paste into the text areas.
  • Can I use this for real production data?: Use at your own risk. For secrets (passwords, tokens), prefer controlled environments and your company policies. And always review the generated contents. Never trust blindly things you see on the internet.

Sample payload to try

  • See also the larger "Code Snippets" sample; paste this excerpt to try locally: Example — const data = JSON.parse(jsonText); const json = JSON.stringify(data, null, 2);

Tool guide

  • What JSON is Standard payload format for web integrations.

  • What JavaScript is and where it is used Core language for browsers and also used in Node.js backend and automation scripts.

  • What object the tool manipulates Input JSON converted into a JavaScript object literal ready for code use.

  • What the tool does Generates snippet with object, parse (JSON.parse), and serialization (JSON.stringify).

  • Parse/generate examples in JavaScript const data = JSON.parse(jsonText) and const json = JSON.stringify(data, null, 2).

Code Snippets

Code example
const data = JSON.parse(jsonText);
const json = JSON.stringify(data, null, 2);

Example

const data = JSON.parse(jsonText);
const json = JSON.stringify(data, null, 2);

FAQ

What is this tool for?

It runs fully in your browser: useful to validate, format, or convert data in everyday development.

Are my inputs sent to a server?

Processing happens locally with JavaScript. We do not store what you paste into the text areas.

Can I use this for real production data?

Use at your own risk. For secrets (passwords, tokens), prefer controlled environments and your company policies. And always review the generated contents. Never trust blindly things you see on the internet.