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AI JSONMedic
AI JSON Fixer — 14-stage repair engine

AI JSON Fixer — Repair Broken JSON Instantly Free

The fastest AI-powered JSON repair tool online. Fix broken JSON from ChatGPT, Claude, Gemini, n8n, and any LLM output in under 1 second. Plain-English explanations. No signup, no install.

JSON never sent to serverFixed in <1s 12,875,916 repairs No signup ever 14 error types

10 error types handled

AI JSON Errors We Fix Automatically

Markdown Fences✓ Fixed
```json {"a":1} ```
↓ repaired
{"a":1}

ChatGPT wraps JSON in markdown code blocks by default

Trailing Commas✓ Fixed
{"a":1, "b":2,}
↓ repaired
{"a":1, "b":2}

AI models frequently add trailing commas that JSON rejects

Python Booleans✓ Fixed
{"active": True}
↓ repaired
{"active": true}

Models trained on Python use True/False/None instead of JSON literals

Single Quotes✓ Fixed
{'key': 'value'}
↓ repaired
{"key": "value"}

JavaScript-style single quotes aren't valid JSON

Truncation✓ Fixed
{"data": [1, 2
↓ repaired
{"data": [1, 2]}

Streaming responses cut off at token limits leaving open brackets

JS Comments✓ Fixed
{"a":1 // note }
↓ repaired
{"a":1 }

LLMs add // and /* */ comments that break JSON parsers

Unquoted Keys✓ Fixed
{name: "Alice"}
↓ repaired
{"name": "Alice"}

AI sometimes outputs JavaScript object literals with bare keys

Invalid Values✓ Fixed
{"val": NaN}
↓ repaired
{"val": null}

NaN, Infinity, and undefined are JavaScript-only — not valid JSON

Why You Need a JSON Fixer for AI Output

Large language models like ChatGPT, Claude, and Gemini frequently generate invalid JSON that breaks your applications. Whether you need to fix JSON online from an API response or repair JSON from a chatbot, the problem is the same: AI models produce output that looks right but fails standard JSON parsers.

Common issues include markdown code fences (```json), Python-style booleans (True/False), trailing commas, and truncated responses from streaming APIs. A standard JSON validator only tells you it's broken — our JSON fixer actually repairs it.

Streaming responses create another class of problems: when an LLM hits its token limit mid-response, the JSON is simply cut off — leaving unclosed brackets, arrays, and strings. You need a JSON repair tool that understands these AI-specific failure patterns.

How Our Online JSON Fixer Works

AI JSONMedic is the most advanced JSON fixer online. Unlike generic validators, it understands AI-specific error patterns and repairs them automatically in a 14-stage pipeline:

  1. Strip markdown code fences and prose prefixes
  2. Remove encoding artifacts (BOM, null bytes)
  3. Strip JavaScript and Python comments
  4. Convert Python-style booleans (True/False/None)
  5. Replace invalid values (NaN, Infinity, undefined)
  6. Convert single-quoted strings to double-quoted
  7. Quote unquoted object keys
  8. Remove trailing commas
  9. Insert missing commas between values
  10. Repair truncated/incomplete JSON structures
  11. Validate and format the result
  12. Detect duplicate keys (warning)

Every stage tracks exactly what it changed, so you always get a complete repair report — not a black box.

Who Uses This JSON Fixer

Thousands of developers use AI JSONMedic to fix JSON online every day — from backend engineers integrating LLM APIs, to automation builders fixing JSON in n8n and Make.com workflows, to data engineers repairing JSON from AI pipeline output. If you've ever pasted ChatGPT output into your code and got a parse error, this JSON repair tool is built for you.

Frequently Asked Questions

Yes. AI JSONMedic specifically detects and fixes the most common ChatGPT JSON errors: markdown code fence wrapping (```json), trailing commas, Python-style boolean values (True/False), and truncated responses from streaming.

No. All JSON repair processing happens in your browser using client-side JavaScript. Your JSON never reaches our servers. We do not store, log, or analyze the content you paste.

AI JSONMedic fixes: markdown code fences, trailing commas, single quotes, unquoted keys, Python booleans (True/False/None), NaN/Infinity/undefined values, JavaScript comments, truncated/incomplete JSON, missing commas, and UTF-8 BOM characters.

Yes. When an LLM response is cut off mid-stream due to token limits, the JSON is left with unclosed brackets and strings. AI JSONMedic detects this and intelligently closes open structures.

Yes. Paste your broken workflow JSON and AI JSONMedic fixes JavaScript-style object literals, single quotes, unquoted keys, and Python booleans — all common in n8n AI node output.

Yes. Send a POST request to /api/repair with your JSON in the request body. The endpoint returns repaired JSON with a full repair report. See the API documentation for request format and examples.

The tool handles JSON documents up to 2MB. For larger documents, split them before pasting or use the API endpoint directly.

JSONLint validates JSON — it tells you something is broken. AI JSONMedic repairs it, explains every fix in plain English, and is specifically designed for the failure patterns produced by AI language models. See the full feature comparison for a side-by-side breakdown.

How AI JSONMedic Compares

vs JSONLintvs JSON Editor Onlinevs CodeBeautifyvs JSONFormatter.org