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The AI JSON Surgeon
Fix LLM Bugs in One Click
Paste broken JSON from ChatGPT, Claude, or any AI. Get perfect JSON back instantly — with a plain-English explanation of what was wrong.
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broken-llm-output.json — 6 errors detected
✗ Broken (from ChatGPT)
{
"model": "gpt-4o",
"temperature": 0.7,
"messages": [
{
"role": "user",
"content": "Hello", // trailing comma
},
],
status: "active",
result: undefined,
}✓ Repaired (1 click)
{
"model": "gpt-4o",
"temperature": 0.7,
"messages": [
{
"role": "user",
"content": "Hello"
}
],
"status": "active",
"result": null
}🤖 Active Assistant says:
Your JSON had a trailing comma, an unquoted key (status), and an undefined value — classic ChatGPT formatting issues. Fixed 3 problems automatically.
6 LLM Failure Modes. All Fixed.
The exact bugs LLMs produce — and exactly why JSON validators choke on them.
🔴
Trailing commas
Arrays and objects end with , before closing bracket
🟡
Unquoted keys
Object keys like status: instead of "status":
🟠
JS comments
// line comments and /* block comments */ inside JSON
🔵
Markdown fences
JSON wrapped in ```json code blocks from ChatGPT
🟣
Truncated output
LLM cut off mid-response, leaving unclosed brackets
⚪
JS values
undefined, NaN, Infinity where null is required
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$0forever
- ✓ Unlimited formatting & validation
- ✓ Real-time syntax highlighting
- ✓ 10 AI Surgeon fixes / month
- ✓ Copy & download fixed JSON
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- ✓ Active Assistant sidebar
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Why Not Just Use JSONLint?
| Feature | JSONLint / JSONFormatter | JSONFix.tech |
|---|---|---|
| Auto-repair JSON | ❌ | ✅ |
| LLM-specific fixes | ❌ | ✅ |
| Plain-English explanation | ❌ | ✅ |
| Active Assistant sidebar | ❌ | ✅ |
| Trailing comma fix | ❌ (only detects) | ✅ Auto-fix |
| Markdown fence removal | ❌ | ✅ |
| Schema inference | ❌ | ✅ |
| Modern UI | ❌ (2009-era) | ✅ |
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