How to Fix Invalid JSON: A Practical Error-Checking Guide
6 min read · Updated 2026-07-18
When JSON is invalid, the fastest path is to fix the first parser error rather than changing several lines at once. The JSON Validator keeps the document in your browser and shows available line and column details.
Start with the first reported error
A parser stops at the first character that makes the document impossible to read. Later messages can be consequences of that first problem, so make one small correction and validate again.
Check the JSON rules first
Object keys and text values need double quotes. Items need commas between them but never after the final item. Strings cannot contain a literal line break or an unescaped double quote.
{
"project": "YouKit",
"enabled": true
}Use the position as a starting point
The highlighted position tells you where parsing failed, which may be just after the actual mistake. Inspect the preceding token for a missing comma, extra comma, or unclosed quote.
Frequently asked questions
Why does the error point after the real mistake?
The parser reports a problem when it reaches a character that no longer fits the expected structure. The cause is often immediately before that position.
Can a formatter fix invalid JSON?
A formatter can only format data it can parse. Validate and make the intended correction first so values are not guessed or changed.