Is my JSON data sent to a server?

No. All parsing and formatting runs entirely in your browser using the built-in JavaScript `JSON.parse` and `JSON.stringify` APIs. Your data never leaves your machine.

Why does the formatter show a line and column number for errors?

When the browser's JSON parser throws a `SyntaxError`, the tool extracts the character position from the error message and maps it back to a line and column number. This makes it much faster to locate the typo or missing bracket in large JSON.

What does "Sort keys" do?

Sorting keys reorders every object's keys alphabetically at every level of nesting. This makes it easy to compare two JSON objects visually or produce deterministic output for diffing.

What is the minified output useful for?

Minified JSON removes all whitespace, producing the smallest possible string. This is useful when sending JSON in HTTP requests, storing it in a database, or embedding it in code where file size matters.

What do the JSON stats mean?

Object count is the number of `{}` nodes. Array count is the number of `[]` nodes. Key count is the total number of object keys across all objects. Max depth is how many levels of nesting the deepest value sits at.

JSON Formatter & Validator - Pretty Print, Minify, Validate

What does a JSON formatter do?

A JSON formatter takes raw, often compressed or inconsistently indented JSON text and re-serializes it with consistent indentation. The result is easier to read, diff, and debug. This formatter supports 2-space and 4-space indentation (the two most common styles in JavaScript projects), tab indentation (common in Go and other languages), and minification (useful for shrinking payloads for HTTP requests or storage).

JSON validation and error location

Validation is performed by the browser's native JSON.parse: the same parser your JavaScript runtime uses. When the input is invalid, the parser throws a SyntaxError containing a character position (in V8/Chrome/Node) or a line and column number (in Firefox/SpiderMonkey). This formatter extracts that information and displays it as a human-readable "Line X, column Y" message, making it much faster to locate the offending character in large JSON documents.

Key sorting

Enabling Sort keys reorders every object's properties alphabetically at every level of nesting. This is useful for producing deterministic JSON output, for example when comparing two API responses that contain the same data in different key orders, or when diffing configuration files. Sorting is applied before formatting, so the output is fully deterministic regardless of the original key order.

Tree view

The Tree view tab renders the parsed JSON as a collapsible tree. Each object and array can be expanded or collapsed independently. Objects show their key count and arrays show their element count in the collapsed state. This is useful for navigating deeply nested JSON without manually searching through text.

JSON5 and JSONC

Standard JSON has strict rules: no comments, no trailing commas, no single-quoted strings, no unquoted keys. Two popular supersets relax these rules:

JSON5: supports comments, trailing commas, single-quoted strings, unquoted keys, and hex literals. Used in some configuration tools.
JSONC (JSON with Comments): JSON plus C-style // and /* */ comments. Used by VS Code, TypeScript (tsconfig.json), and other tooling.

This formatter validates and formats strict JSON (RFC 8259). JSONC and JSON5 files must be converted to standard JSON first (strip comments, remove trailing commas).

Large JSON performance

This tool handles most JSON files well. For very large files (>5 MB), browser-based tools become slow due to rendering limits. For large JSON, consider command-line tools:

jq . input.json - format and query JSON with the ubiquitous jq tool
python3 -m json.tool input.json - format using Python's standard library
cat input.json | fx - interactive JSON explorer in the terminal