Error 1: Unexpected Token

Message: "Unexpected token ' at position 1"
Cause: Using single quotes instead of double quotes.
Fix: Replace all 'key' with "key" and all 'value' with "value".

Error 2: Trailing Comma

Message: "Unexpected token } at position X"
Cause: A comma after the last item in an object or array.
Fix: Remove the trailing comma: {"a": 1, "b": 2,} → {"a": 1, "b": 2}

Error 3: Missing Comma

Cause: Forgetting the comma between key-value pairs.
Fix: {"a": 1 "b": 2} → {"a": 1, "b": 2}

Error 4: Unescaped Characters

Cause: Including raw newlines or double quotes inside a string.
Fix: Escape with backslash: "say \"hello\"" or "line1\nline2"

Error 5: Incorrect Literals

Cause: Writing True, False, Null with capital letters.
Fix: JSON requires lowercase: true, false, null.

Paste your JSON into JSON Parser Online to identify errors with precise line/position numbers.