JSON Stringify
Convert JavaScript objects and arrays to JSON strings with customizable indentation and HTML escaping. Free, runs entirely in your browser with no data uploaded.
What is JSON Stringify?
JSON.stringify() is a built-in JavaScript method that converts a JavaScript value to a JSON formatted string. This tool provides a visual interface for that conversion with additional features like indentation control and HTML escaping.
How do I use this JSON stringify tool?
Paste or type your JavaScript object or array in the input area. The tool instantly converts it to a JSON string. You can adjust indentation (spaces or tabs) and enable HTML escaping for safe embedding in web pages.
What is the difference between JSON and JavaScript objects?
JSON requires all keys to be wrapped in double quotes and only supports string, number, boolean, null, array and object types. JavaScript objects allow unquoted keys, single quotes, and can contain functions, undefined, and Symbols.
How are circular references handled?
JSON.stringify() throws an error when it encounters a circular reference. This tool detects circular references and displays a clear error message so you can fix the data structure.
Can I customize the output indentation?
Yes. You can set the indentation to any number of spaces or use tabs. Use 0 or empty for compact output with no extra whitespace, which is ideal for data transfer.
What does HTML escaping do?
HTML escaping converts characters like <, >, &, " and ' into their HTML entity equivalents (<, >, &, etc.). This prevents the JSON string from breaking HTML when embedded in a script tag or HTML attribute.
Does this tool work in all browsers?
Yes. JSON.stringify() is a standard method supported by all modern browsers including Chrome, Firefox, Safari, and Edge. No extensions or plugins are needed.
How can I check if the output is valid JSON?
The tool generates syntactically correct JSON by using the native JSON.stringify() method. You can verify the result by pasting it into any JSON validator or using JSON.parse() in the browser console.
Is my data sent to a server?
No. All processing happens locally in your browser using JavaScript. Your data never leaves your device, making this tool safe for sensitive information.
What values are ignored by JSON.stringify()?
JSON.stringify() ignores undefined values, functions, and Symbol-keyed properties in objects. In arrays, these values are replaced with null. Use a replacer function to customize the serialization behavior.
How to Use JSON Stringify
Convert JavaScript objects and arrays into JSON strings with your choice of indentation and optional HTML escaping. Everything is processed locally in your browser, and no code you enter is uploaded.
- Enter the JavaScript object or array literal you want to serialize in the input area.
- Under “Indentation:”, choose “Spaces” or “Tabs” depending on how the output should be indented.
- Set the indent width in the “Spaces:” field, for example 2 or 4 spaces per level.
- Turn on “Escape HTML” so characters like < and > become safe escape sequences and can't break page markup.
- Copy the resulting JSON string and paste it into your code, config, or API payload.
Enable “Escape HTML” whenever the JSON will be embedded in an HTML page, so a closing tag such as </script> cannot escape the string and inject code.
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