Text, Data & Code tool
JSON Formatter & Validator
Make JSON readable, find syntax errors and create compact output. Preserve number tokens and key order, then copy or download the result privately in your browser.
Readable JSON. Exact values.
Format or compact JSON without rounding large numbers or changing key order.
0 / 2,000,000 characters
No automatic repairs, code execution, tracking fields or branding are added to your data. Clear removes the working text from this tool. JSON is limited to 100 nesting levels; tables to 50,000 rows / 200,000 cells.
Processed privately in your browser — your entries are not uploaded.
Good to know
How this tool works
Paste JSON or load a UTF-8 file, then choose Validate & format or Minify JSON. Formatting changes whitespace only: number tokens, escaped strings and key order are preserved. Duplicate keys are rejected rather than silently overwritten. Comments and trailing commas are not valid JSON.
Frequently asked questions
What is JSON Formatter & Validator useful for?
Validate, format or compact JSON without rounding large numbers. Validate a small sample before processing important data, and keep a copy of the original input.
Is my information stored?
Your text is processed locally in a browser worker. It is not uploaded by this tool or saved in browser storage. Clear releases the working input and result. Downloads remain in your normal download folder.
Will large numbers or leading zeros change?
JSON number tokens are kept exactly as written. CSV imports produce JSON strings, so leading zeros remain. Spreadsheet software may reinterpret CSV values when opened; import columns as text to protect IDs and long numbers.
What does formula protection do?
CSV export can prefix formula-like cells with an apostrophe to help prevent spreadsheet execution. This changes those cells, including negative numbers. The result reports how many were changed. Turn it off only when exact raw cells are needed and the data is trusted.
Can CSV keep all JSON information?
No. CSV has no native value types. Null and missing fields become empty cells, nested structures are rejected, and arrays of objects use the union of their columns in first-seen order. The converter explains these limitations rather than silently guessing.