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Fix "Expected double-quoted property name in JSON"

Solve strict JSON parsing errors caused by trailing commas, single quotes, or unquoted keys.

The Problem (Error Root Cause)Exception

Your JSON parser throws "Expected double-quoted property name". You are likely using JavaScript object literal syntax (like single quotes or unquoted keys) which is strictly forbidden in the JSON spec.

Identified via runtime validation & stack traces

The Solution (Step-by-Step Fix)Verified

Wrap all keys in double quotes `""`. Change all string values to double quotes. Remove trailing commas from the last item in objects or arrays.

Deterministic, non-destructive resolution

Code Standard: Bad Pattern vs Verified Fix

Live Syntax

Anti-Pattern vs Verified Fix

1// ❌ Bad: JS object syntax (invalid JSON)
2{ name: 'John', age: 30, }
3 
4// ✅ Good: Valid strict JSON
5{ "name": "John", "age": 30 }

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Frequently Asked Questions

Q:Why does JSON strictly require double quotes?

The JSON spec (RFC 8259) enforces double quotes to make parsing simpler and identical across dozens of programming languages.

Q:Can I auto-fix this?

Yes! Paste your malformed JS object into our JSON Formatter and it will automatically quote keys and fix trailing commas.

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