JSON Formatter, Validator & Auto-Fixer
Format, beautify, and validate JSON data. Automatically repair trailing commas, single quotes, and unquoted keys.
Transparent Syntax Auto-Repair
Most online validators merely report an obscure syntax error. Tooltiva goes further: our intelligent Auto-Fixer repairs trailing commas in lists and dictionaries, converts JavaScript single-quotes to standard double-quotes, quotes bare keys, and strips comments. Crucially, we never modify data silently—every change is logged with exact counts and an instant undo option.
RFC 8259 Compliance & Privacy
Pasting production API keys, internal configs, or database records into third-party formatting websites creates security and privacy exposure. Tooltiva executes all formatting and syntax checks locally in your browser's JavaScript engine. Your payloads are not sent by the application to an external processing service.
Common JSON Errors and How to Prevent Them
- Trailing commas: Placing a comma after the final property (e.g.
{ "a": 1, }) is permitted in JavaScript, but forbidden in strict JSON (RFC 8259). - Single quotes: JSON strictly requires double quotation marks (
") around strings and property keys. - Unquoted keys: Python dictionaries or JS object literals like
{ name: "Alice" }must have their keys wrapped in double quotes. - Comments: Neither single-line
//nor block/* */comments are permitted in valid JSON data.