Fix "Expecting value: line 1 column 1 (char 0)" (Python)

Python · JSON error

By JSON Wallet Editorial Team · August 31, 2026

json.decoder.JSONDecodeError: Expecting value: line 1 column 1 (char 0)Expecting value: line 1 column 1 (char 0)simplejson.errors.JSONDecodeError: Expecting value

Opens the editor with a broken example loaded and repaired, entirely in your browser — nothing is uploaded.

What causes it

json.loads() raises JSONDecodeError: Expecting value when the text it receives does not begin with a valid JSON value. "Line 1 column 1 (char 0)" means the problem is at the very first character, which almost always means the input is not JSON at all:

Empty input — json.loads('') or a response with no body.
An HTML or plain-text response — you called response.json() on a requests result that returned an error page. Print response.text and response.status_code first.
Python literals, not JSON — single quotes, None, True/False, or a trailing comma copied from a Python dict. Those are not valid JSON.

How to fix it

Print repr(text) right before json.loads() to see whether it is empty or not JSON.
For requests, check response.status_code and response.headers['content-type'] before calling .json().
If the text uses single quotes, None, True or False, it is a Python literal — convert to valid JSON (double quotes, null, true/false).
Paste the text into JSON Wallet to convert Python-style pseudo-JSON into strict, valid JSON.

Before and after

Broken:

{'name': 'Ada', 'active': True, 'note': None}

Fixed:

{"name": "Ada", "active": true, "note": null}

Want to fix your own JSON instead of the example? Open the editor, paste it in, and click Repair — it runs entirely in your browser.

Frequently asked questions

Why does char 0 mean the whole thing is wrong?

"char 0" is the first character. If the parser fails there, it never found a valid JSON value to begin with — the input is empty or is not JSON, rather than having a small typo deeper in.

My data uses single quotes and True/False — is that JSON?

No. That is a Python dict printed as a string. JSON requires double quotes and lowercase true/false/null. Convert it before parsing.

Related JSON errors

Fix JSON With Single Quotes

JSON only allows double quotes. Single quotes — common when copying object literals from JavaScript or Python — are rejected by every strict parser.

Fix "Unexpected token in JSON at position N"

The most common JSON.parse() error. It means the parser hit a character it did not expect — usually HTML, an already-parsed object, or a stray token.

For a full reference of JSON mistakes, read Common JSON errors and how to fix them.