JSON Formatter & Validator

JSON Formatter, Validator, Beautifier & Viewer

Paste JSON or open a local UTF-8 JSON file, then choose Format to pretty-print it with 2, 3 or 4 spaces, or tabs. Use Minify to remove whitespace outside strings, or Validate to check the syntax and inspect the result. Switch between Code and Tree to read the output, find a value or explore nested objects and arrays. All processing happens locally in your browser.

JSON Viewer with a Collapsible Tree

Switch to Tree after formatting or validating a document. Expand and collapse objects and arrays, search keys and values across collapsed branches, and use the previous and next match buttons to explore results in context. Select a node to copy its complete JSON value or its JSON Pointer. Pointer paths escape slashes and tildes; the root pointer is an empty string. Duplicate keys are preserved, but ambiguous pointers cannot be copied.

JSON Validator with Detailed Errors

Validate checks strict JSON syntax and reports the line and column of an error. It rejects trailing commas, single-quoted strings, unmatched brackets, unescaped control characters, missing commas and unquoted object keys. It does not accept comments, JSON5 or JSONC. If you change the input or validation fails, the last successful result remains visible with a notice; run Format or Validate again before copying or downloading an updated result.

Features

Choose your indentation, format or minify JSON, and download the result as a .json file. Numbers retain every digit, decimal and exponent; duplicate keys, key order and string escapes are preserved. Small documents have syntax highlighting; larger ones use readable plain text. The tool supports up to 2 MiB of input, 50,000 values, 128 nesting levels and 8 MiB of formatted output. Tree navigation displays 500 rows at a time, while search covers the whole document. No account or upload is needed.

Frequently Asked Questions

What is the difference between JSON formatter, beautifier, viewer, and validator?

A JSON formatter or beautifier adds consistent indentation. A JSON viewer helps you inspect the document with a collapsible tree and key/value search. A JSON validator checks syntax and reports the line and column of an error. A JSON minifier removes whitespace outside strings to produce compact JSON. This tool combines all four on one page.

How do I format minified JSON to make it readable?

Paste your minified JSON or open a local .json file. Choose 2, 3 or 4 spaces, or tabs, and click Format. Inspect the Code or Tree view, then copy or download the result. Minify removes the formatting again without changing whitespace inside string values.

How do I find errors in invalid JSON?

Click Validate to check the document. Invalid JSON is reported with a line and column so you can inspect the problem. Check for missing commas, unmatched brackets, trailing commas, unescaped characters, or single quotes instead of double quotes. JSON does not allow comments. Correct the input and run Validate again to update the result.

Is my JSON data private?

Yes. Formatting, validation, tree navigation and search run locally in your browser. JSON you paste or open is not uploaded, included in analytics events, or saved by this tool. Downloading creates a local file. Opening Phoenix Code does not automatically transfer your data.

Last updated: September 28, 2026