How to Fix Broken JSON: Multi-Pass Automated Repair Engine
Unlike tolerant JavaScript object literals or Python dictionaries, the JSON standard (RFC 8259) is notoriously strict. A single misplaced trailing comma, an unquoted object key, or a stray code comment will trigger fatal parse errors (SyntaxError: Unexpected token) across virtually every programming language runtime. TinyTools JSON Repair diagnoses and repairs these malformed payloads automatically.
How to Repair Invalid JSON
- Paste Malformed Payload: Paste your broken JSON or Python dictionary into the left editor.
- Inspect Automated Fixes: The repair engine automatically removes comments, wraps keys in double quotes, removes trailing commas, and normalizes booleans, displaying an audit log of every change made.
- Copy or Download: Copy your newly validated, pretty-printed JSON directly to your clipboard or download it as a
.jsonfile.
Code Example: Broken Input vs Repaired Output
Here is a malformed snippet containing 4 distinct syntax violations (unquoted keys, single quotes, Python True, and a trailing comma):
{
server: 'aws-east-1',
ready: True,
ports: [80, 443,],
}
After automated repair, all keys are quoted, single quotes are replaced, Python booleans are lowercased, and trailing commas are stripped:
{
"server": "aws-east-1",
"ready": true,
"ports": [
80,
443
]
}
The 6 Most Common JSON Syntax Errors & How We Fix Them
1. Trailing Commas
Commas after the final item in an object or array (e.g., {"a": 1,}) break JSON parsers. We strip trailing commas before closing braces and brackets.
2. Single Quotes Instead of Double Quotes
JSON strictly mandates double quotes ("). Strings or keys enclosed in single quotes ('key': 'value') are converted automatically.
3. Bare / Unquoted Property Keys
JavaScript object notation allows unquoted keys like { name: "John" }. JSON requires quoted keys ({ "name": "John" }).
4. Python Booleans & None
Copying Python dict outputs introduces capitalized keywords (True, False, None). We convert them to true, false, and null.
5. Stray Comments
Developers often annotate configs with // comments or /* block comments */. Our parser strips comments while preserving content inside quotes.
6. Missing Closing Braces
Truncated payloads copied from terminals or log files often miss closing } or ] tokens. We automatically balance open structures.