Format · Validate · Diff · Java POJO · TypeScript · CSV · Escape · JSONPath
Fix invalid JSON automatically — single quotes, trailing commas, unquoted keys, comments, and more.
Replaces 'single quotes' with "double quotes" around keys and string values.
Strips extra commas before closing brackets and braces like {"a":1,} → {"a":1}.
Wraps unquoted object keys in double quotes: {name: "Tom"} → {"name": "Tom"}.
Removes // line comments, /* block comments */, Python-style # comments.
Converts Python True/False/None and JS undefined to valid JSON true/false/null.
Detects and appends missing closing } and ] to make JSON parseable.