📦 JSON Formatter & Validator

Using JSON Formatter & Validator

Turn a compressed API response into readable, indented JSON, find the syntax error that stops it parsing, or minify it again before pasting it into a config.

How to use it

1. Paste JSON into the editor, or click Load Sample to see how the tool behaves first.
2. Click Prettify (2 Spaces) or Prettify (4 Spaces) to indent it; the formatted result replaces the text in the editor.
3. If an error appears instead, read the message and check the usual causes: a missing comma, an unquoted key, or a trailing comma after the last item.
4. Click Minify JSON when you need a single line, then Copy Output. Clear empties the editor.

Worked example

Input and settings

{"id": 12, "tags": ["a","b"]} → Minify JSON

Expected result

{"id":12,"tags":["a","b"]}

Limits and common mistakes

• Passing here means the text is valid JSON syntax, not that it has the fields and types your API expects.
• JavaScript-style comments, trailing commas and single quotes are rejected because the JSON standard does not allow them.
• Integers larger than 9,007,199,254,740,991 lose precision when parsed, so long numeric IDs can change silently; keep such IDs as strings.
• If an object repeats a key, only the last value survives formatting.

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