JSONDecodeError: Expecting ',' delimiter
Python's json parser reached a point where it needed a comma to separate the next item and found something else — usually a missing comma between two entries, a trailing comma, or an unescaped double quote inside a string. Line X column Y tells you exactly where to look; check that spot and the item just before it.
What the error means
json.loads() was parsing an object or array and expected a , before the next key/value or element. Instead it saw a quote, brace, or bracket. The column number is where it gave up; the real fix is usually one token earlier.
The three causes
1. Missing comma between two key/value pairs or two array items — the most common case.
2. Trailing comma after the last item, e.g. [1, 2, ]. JSON does not allow it (unlike Python literals).
3. Unescaped double quote inside a string, which ends the string early so the parser then expects a comma. Escape it as \".
Fix it
Open the file at line X, column Y. Add the missing comma, remove the trailing one, or escape the stray quote. If the data is really a Python dict with single quotes or True/False/None, do not use json.loads — use ast.literal_eval() or fix the quoting first. Paste the payload above and hit Repair to normalise commas and quotes.
FAQ
The column points at a valid-looking character — why?
The parser reports where it expected the comma, which is the start of the next item. The missing comma belongs at the end of the previous line.
I pasted a Python dict, not JSON — how do I load it?
Use ast.literal_eval() from the ast module; it understands single quotes and True/False/None. json.loads only accepts strict JSON.
Related errors: 'Expecting \':\' delimiter'?
Same family — that one means a colon is missing between a key and its value. Check the key just before the reported column.