Free Online String to JSON Converter

Use Free Online String to JSON Converter, review the result, and keep the original until the output is checked.

Input JSON
JSON Input
Generated String
String Output
Enter JSON and click "Convert to String" to see generated string...
100% browser-side processing — your data is never uploaded to any server. · Per-tool input limit: 1 MB
100% browser-based No upload to server Free to use

Frequently Asked Questions About Free Online String to JSON Converter

Which direction converts what?

String to JSON removes the escaping layer and parses; JSON to string produces the quoted, escaped form to paste into code.

Will it unwrap double encoding?

Each run removes one layer, so a twice-encoded value needs two passes.

Can it fix JSON with trailing commas or comments?

Yes. The repair step removes trailing commas, comments and a byte-order mark, turns single-quoted strings into double-quoted ones and quotes bare member names, then re-reads the document. Values it cannot infer, such as a Python True or a missing closing brace, still need a manual edit.

Why do large numbers change when I format JSON?

JavaScript numbers are IEEE-754 doubles, so most parsers rewrite an integer above 2^53 and lose its tail digits. This page keeps those long literals exactly as you typed them, but a parser elsewhere in your stack will not, so keep such ids as strings in the source document.

What is JSON?

JSON (JavaScript Object Notation) is a lightweight data-interchange format. It uses objects {}, arrays [], strings, numbers, booleans, and null.

Why format JSON?

API responses and config files are often minified. The String to JSON Converter expands them with indentation so you can spot nested keys, validate structure, and debug faster.

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