JSON parsing errors are frustrating, but the error messages actually tell you exactly what's wrong. The trick is knowing how to decode them.
What the Error Message Is Really Telling You
Most JSON parsers give you three pieces of information: what went wrong, where it happened, and sometimes what the parser expected instead. A typical error might say "Unexpected token } in JSON at position 247" or "Expected ',' or '}' after property value in JSON at line 12, column 8". That position or line number is your starting point.
Open your JSON file in a proper text editor (Notepad++ on Windows, VS Code, or even Notepad with line numbers turned on). Navigate to the line or character position mentioned in the error. The problem is usually right there or within a line or two. Don't try to eyeball a 300-line JSON file from the top. Use the error coordinates.
If the error says "position 247", count characters from the start, but most editors let you jump to a specific position using Go To or a search function. In VS Code, press Ctrl+G and type the line number. In Notepad++, Ctrl+G does the same thing.
The Five Most Common JSON Syntax Mistakes
Once you know where to look, here's what you're usually hunting for:
-
Trailing commas: JSON forbids a comma after the last item in an array or object. If you see
{"name": "Alice", "age": 30,}, delete that final comma before the closing brace. -
Missing commas: Forget a comma between properties and the parser chokes.
{"name": "Alice" "age": 30}needs a comma after the first value. -
Single quotes instead of double quotes: JSON only accepts double quotes around strings.
{'name': 'Alice'}is invalid. Change it to{"name": "Alice"}. -
Unescaped quotes or backslashes inside strings: If your string contains a quote or backslash, escape it with a backslash.
"He said "hello""should be"He said \"hello\"". -
Mismatched brackets or braces: Every opening
{needs a closing}, and every[needs a]. Count them, or let your editor highlight matching pairs when you click one.
If you copied JSON from a web page or email, watch out for smart quotes (" " instead of "). Word processors love to insert these, but JSON parsers reject them instantly. Replace all curly quotes with straight double quotes.
Use a Validator to Pinpoint Obscure Problems
Sometimes the error message points you to line 47, but the real mistake is three lines earlier. JSON validators can help. Paste your JSON into a free online validator like JSONLint or use a built-in validator in your editor. These tools often give clearer explanations than raw parser errors.
Many code editors (VS Code, Sublime Text, Notepad++) can validate JSON as you type. VS Code will underline syntax errors in red and show a helpful tooltip when you hover over the problem. If you work with JSON regularly, this real-time feedback saves hours.
Be careful with validators that "fix" your JSON automatically. Some will silently change your data (converting numbers to strings, for example) or strip out comments that your specific parser might have supported. Use them to identify problems, then fix the original file by hand.
When the Error Message Lies (Or You Think It Does)
Occasionally the error points to line 50, but the real problem is on line 30. This happens when the parser kept reading, hoping you'd close a string or array, and finally gave up much later. If you can't spot anything wrong at the reported line, scroll up and look for an unclosed quote or bracket.
Another culprit: invisible characters. If you copied JSON from a PDF or a terminal, you might have zero-width spaces, non-breaking spaces, or other Unicode gremlins that look like nothing but break parsing. Select the area around the error and retype it from scratch. Or paste your JSON into a plain-text editor that shows hidden characters.
If your JSON file is supposed to have comments (some parsers allow // comments or /* block comments */ as an extension), but you're using a strict parser, you'll get errors. Standard JSON doesn't support comments at all. Strip them out or switch to a parser that accepts JSON5 or JSONC.
Preventing Errors in the First Place
The best way to avoid JSON parsing errors is to generate JSON programmatically instead of writing it by hand. If you're exporting data from Excel, a database, or an API, let the software handle the quoting, escaping, and commas. In Excel, for example, you can export to CSV and then convert to JSON with a script, or use Power Query to shape the data correctly.
When you do need to edit JSON manually, use an editor with syntax highlighting and bracket matching. Even Notepad++ (free on Windows) will colour-code your JSON and show you when braces don't match. If you're working in Excel or Word to prepare data, remember that those tools aren't designed for code. Copy your finished JSON into a proper text editor for a final sanity check.
Keep a backup of working JSON before you make changes. It's much easier to compare a broken version against a known-good one than to reconstruct valid JSON from memory. Version control (Git) is overkill for a single file, but even saving a copy as config_backup.json will save you when you accidentally delete a bracket.
Debugging JSON errors gets faster with practice. Once you've fixed a few trailing commas and mismatched quotes, you'll recognise the patterns instantly. If you're working with JSON as part of a larger project in Excel or Access, having reliable software makes everything smoother. Keyzzone supplies genuine Microsoft Office 2021 Professional Plus licences that keep your productivity tools up to date and fully supported.