JSON Is Not a JavaScript Object Literal
A payload like { name: 'Ada', } may look natural in JavaScript, but it is not valid JSON. JSON requires double-quoted property names and strings, and it rejects the final comma before a closing brace or bracket.
The same issue happens when a configuration file includes // comments, Python values such as True or None, or a copied log fragment that is only part of a larger document.
Repair the Common Errors in a Safe Order
First, identify whether the input is intended to be JSON at all. Then remove comments, quote bare keys, replace clearly-delimited single-quoted strings, remove trailing commas, and validate the result with a strict parser.
Do not blindly replace every apostrophe with a double quote. Text such as O'Reilly or escaped content can make a global replacement corrupt the data. Use a formatter’s repair preview or inspect the changed regions before copying the output onward.
Repair tools can make malformed data parseable; they cannot prove that the repaired data means what the sender intended. Treat the output as a draft until it validates against the expected schema.
Validate After Repair
A successfully parsed JSON document can still be wrong for your application. Check required fields, value types, nested objects, and identifier formats after syntax repair.
For sensitive payloads, use a local browser formatter or your approved development tools. The goal is to avoid turning a syntax fix into a data-handling incident.