JSON Parser
Paste raw JSON text and the parser checks its structure, validates the syntax, and displays a clean formatted result so you can see exactly what the data contains. Everything runs in your browser — no server, no sign-up.
What is a JSON Parser?
A JSON parser reads a string of JSON text and converts it into a data structure — an object, array, number, string, boolean, or null. Parsing is the first step in working with any JSON payload: before you can read a value, the parser must confirm the text is syntactically valid and build an in-memory representation.
This online parser uses the browser's native JSON.parse(), which is fast and conforms to RFC 8259. If parsing fails, the tool shows the error message and highlights the offending line.
JSON Data Types
| Type | Example | Notes |
|---|---|---|
| String | "hello world" | Must use double quotes |
| Number | 42 or 3.14 | Integers and floats; no NaN or Infinity |
| Boolean | true / false | Lowercase only |
| Null | null | Lowercase only; undefined is not valid |
| Object | {"key": "value"} | Keys must be strings |
| Array | [1, "two", true] | Ordered, mixed types allowed |
Frequently Asked Questions
What does JSON.parse() do?
JSON.parse() is a JavaScript built-in that reads a JSON string and returns a corresponding JavaScript value. If the string is not valid JSON, it throws a SyntaxError. This tool wraps that function and shows you the error in a readable way.
Can I parse a JSON array with this tool?
Yes. A JSON document can be any valid JSON value at its root — object, array, string, number, boolean, or null. Paste an array like [1,2,3] and it will parse and display correctly.
Why does my JSON fail to parse?
Common causes include: trailing commas, single-quoted strings, unquoted keys, stray JavaScript expressions like undefined, or a missing closing bracket. The error message and highlighted line tell you exactly where to look.
Is there a size limit for JSON I can parse?
There is no hard limit imposed by this tool. Parsing happens client-side, so practical limits depend on your browser's memory. Files up to tens of megabytes parse without issues in most browsers.
How is parsing different from formatting?
Parsing converts text into a data structure and validates syntax. Formatting (beautifying) converts a data structure back into a human-readable string with indentation. This tool does both: it parses your input and then re-serialises it with clean formatting.
Can I parse nested JSON?
Yes. JSON supports deeply nested objects and arrays. The formatter will display the full hierarchy with proper indentation regardless of how many levels deep the nesting goes.
Frequently Asked Questions
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