Expecting property name enclosed in double quotes

What the parser tripped over

The error appears wherever the parser expects a key. One of these is usually sitting there instead:

• Single quotes, as in {'name': 'Maya'}. That’s exactly how Python prints a dictionary, which is a strong hint about where the text came from.
• No quotes at all, as in {name: "Maya"}. JavaScript code allows it, and the browser console displays objects this way, but JSON doesn’t.
• A trailing comma, as in {"a": 1,}. After a comma the parser expects another key, and finds }.
• Curly quotes, as in {“name”: “Maya”}. Word, Pages and Google Docs swap straight quotes for curly ones as you type, and so do Macs and iPhones with smart quotes turned on. The JSON looks right, but parsers only accept the straight " character, so it fails at the first key. Fix My JSON swaps them back and leaves apostrophes inside your values alone. To stop it happening, write JSON in a code editor rather than a document. On a Mac, the setting is “Use smart quotes and dashes” in the keyboard’s text input options, and in Word it’s the straight quotes option under AutoFormat As You Type.
• A comment, such as // a note. Some config formats, like VS Code’s settings files, allow comments, but standard JSON parsers don’t. JSONC to JSON removes them.

Fixing it in Python

The usual cause is turning a dictionary into text with str(), print(), or an f-string. Those write Python syntax, not JSON. json.dumps() writes the real thing:

import json

data = {"name": "Maya", "active": True}

str(data)         # {'name': 'Maya', 'active': True}   not JSON
json.dumps(data)  # {"name": "Maya", "active": true}   JSON

Sometimes you can’t change the code that sends you dictionary-style text. In that case, read it with ast.literal_eval(), which understands Python literals but won’t run code. Avoid eval() here, because it will run anything in the text.

import ast, json

data = ast.literal_eval("{'name': 'Maya', 'active': True}")
json.dumps(data)  # '{"name": "Maya", "active": true}'

Fixing it in JavaScript

If you’re building JSON with template strings, switch to JSON.stringify(value). It quotes every key for you, and escapes the values too. If you’re reading a config file that’s meant to have comments or unquoted keys, it isn’t JSON. Read it with a JSON5 parser instead of JSON.parse.

The same error elsewhere