🧩 JSON Formatter & Validator
Format JSON, detect syntax errors and copy readable output.
How to use this utility
Enter your own content in the field above. The result is generated directly in your browser without creating an account. Check the output before using it in a published document or production workflow.
How your input is processed
Your input is processed in the open page without being uploaded to an AI service. The prompt builder prepares editable text for a separate assistant; it does not call an AI model. Keep a separate copy of work you want to save.
Helpful tip
For important work, keep a copy of your original input and check formatting after pasting the result into another application.
Use JSON, not JavaScript object syntax
JSON requires double-quoted property names and strings. It does not accept comments, trailing commas, single-quoted strings, or unquoted keys. For example, {"active":true,"items":[1,2]} is valid input; {active:true,} is not.
The formatter parses the input and serializes it with two-space indentation. It does not validate against a business schema or prove that an API will accept the values. Duplicate object keys can be collapsed by parsing, so do not rely on this tool to preserve or detect duplicates.
Precision and production use
JavaScript numbers have precision limits. This implementation refuses unsafe integers and non-finite parsed values rather than silently publishing a changed long identifier. Put identifiers such as account numbers in quoted strings when that matches the data contract. Do not upload secrets or payment data to illustrate a formatting issue.
After formatting, validate the result in the actual system or schema that will consume it. Copying valid JSON is only the formatting step, not a deployment or an API submission.