JSON Pretty Printer
Free online JSON pretty printer. Paste minified, raw, or compact JSON data to get a perfectly aligned, readable block of clean JSON code.
JSON Input
How to Format and Validate JSON Online
- Paste or Upload: Insert your raw JSON string or drag-and-drop a
.jsonfile into the editor. - Select Indentation: Choose 2 spaces (standard web), 4 spaces (readable), or Minify (single-line compact).
- Inspect and Fix: The real-time validator highlights syntax errors, unescaped characters, or missing quotes immediately.
- Copy or Export: Copy the formatted output with one click or download the clean file.
Common JSON Syntax Errors and Fixes
- Trailing Commas: Arrays and objects cannot end with a comma before the closing bracket (e.g.,
{"a": 1,}is invalid). Remove any lingering trailing commas. - Single Quotes: RFC 8259 requires double quotes around keys and string values (e.g.,
'key'must be"key"). Replace single quotes with double quotes. - Unquoted Keys: Object keys must always be enclosed in quotation marks. Unquoted JavaScript-style keys (e.g.,
{name: "value"}) will fail validation. - Unescaped Characters: Special characters like newlines (
\n), tabs (\t), or backslashes within string values must be properly escaped.
Secure Client-Side JSON & TOON Formatting
Data privacy is critical for developers. This formatter processes all inputs locally in your browser using high-speed Web Workers. No payload strings, configurations, API keys, or JSON data are ever logged or uploaded to external servers, providing full compliance with enterprise confidentiality requirements.