How to Format and Validate JSON Without an IDE

Broken JSON usually fails for simple reasons: a trailing comma, a single quote instead of double quotes, or a truncated paste from a log. You do not always need to open VS Code. A browser formatter can pretty-print nested objects and surface the first parse error so you can repair payloads quickly.

Step-by-step

1. Open the JSON Formatter.
2. Paste the full response or config file—including the outer braces or brackets.
3. Run Format / Validate and read any error message carefully.
4. Fix the reported line (often a trailing comma) and re-check.
5. Minify only when you need a compact body for an API gateway or embed.

Common mistakes

• JSON requires double quotes around property names and string values.
• Comments (`//`) are invalid in strict JSON—even if JavaScript allows them.
• NaN and Infinity are not valid JSON numbers.
• Binary or blob fields should be encoded (often Base64) as strings.

Moving data further

Need a spreadsheet? Convert arrays of objects with JSON to CSV. Coming from Excel? Start with CSV to JSON, then format. For tokens that look opaque, the JWT Decoder shows claims without verifying signatures—never paste production secrets into untrusted environments.