Data & JSON

JSON Formatter & Validator

Pretty print, minify, and validate JSON documents with exact syntax error locations, document metrics, and interactive tree view. Runs 100% locally in your browser.

● LOCAL ● NO NETWORK ● RFC 8259

JSON Input

Indent:

Bytes: 0 B Chars: 0 Lines: 0 Status: Empty

Formatted Output

JSON Tool Cluster:

Need to compare two JSON documents? Open JSON Diff & Comparison.
Need to convert between YAML or CSV? Open JSON ↔ YAML ↔ CSV Converter.
Need TypeScript types from JSON? Open JSON → TypeScript Generator.
Need to validate against a schema? Open JSON Schema Validator.

About JSON Formatting & Validation

JavaScript Object Notation (JSON) is a lightweight, text-based, language-independent data interchange format defined by RFC 8259 and ECMA-404. Strict JSON requires double-quoted strings, does not allow comments or trailing commas, and distinguishes between objects, arrays, numbers, strings, booleans, and null.

Worked JSON examples

Inspect a nested API response

{"status":"ok","users":[{"id":1,"name":"Ada"}],"next":null}

Pretty Print expands the users array. View Tree lets you inspect its structure without changing the data.

Preserve Unicode and escapes

{"greeting":"こんにちは","message":"Line one\nLine two","ready":true}

Unicode stays readable. The escaped newline stays inside the message string; booleans are unquoted.

Keep a large identifier exact

{"accountId":"9007199254740993","balance":12.5}

Keep identifiers above JavaScript’s safe integer range as strings. Native JSON parsing can round large numeric values; formatting cannot recover lost precision.

Common Syntax Errors & Solutions

Trailing Commas: {"a": 1, "b": 2,} is invalid in strict JSON. The trailing comma after 2 causes a parse error.
Single Quotes: JSON keys and string values must strictly use double quotes ("key"), not single quotes ('key').
Unquoted Keys: JavaScript object literal syntax allows unquoted keys ({name: "Alice"}), but standard JSON requires {"name": "Alice"}.
Numbers with Leading Zeros: Octal numbers and leading zeros like 0123 are forbidden in JSON.

Privacy & Local Execution

All formatting, minification, tree construction, and validation execute directly inside your browser runtime. QuikTech does not transmit your JSON payloads across the network.