AI Data Prep Tool Free Interactive Tool · Zero Logging

Free Broken JSON Fixer — Repair Truncated LLM JSON, Single Quotes & Trailing Commas

Strip Markdown fences, fix single quotes & trailing commas, close truncated brackets, and validate against JSON Schema. Paste broken, truncated, or Markdown-fenced JSON from ChatGPT, Claude, or Llama and deterministically repair syntax errors in under 1 ms.

Interactive Edge Playground

Try It Live (`POST /v1/json-heal`)

Ready

Paste broken JSON inside the raw field (and optionally attach a target schema) and press Run Live Tool. Powered by Broken JSON & LLM Output Healer API (POST /v1/json-heal).

Input Payload (Editable JSON)

Live Edge Worker Output

{
  "ok": true,
  "data": {
    "valid": true,
    "data": {
      "name": "Ada",
      "active": true,
      "tags": [
        "ai",
        "edge"
      ]
    },
    "healed_json": "{\"name\":\"Ada\",\"active\":true,\"tags\":[\"ai\",\"edge\"]}",
    "repairs": [
      "stripped_markdown_fence",
      "normalized_single_quotes",
      "normalized_literals",
      "removed_trailing_commas",
      "closed_truncated_containers"
    ],
    "schema_valid": null,
    "schema_errors": []
  },
  "meta": {
    "request_id": "req_jh_01",
    "ms": 1
  }
}

What This Free Tool Checks & Validates

Deterministic single-pass FSM scanner (~0.2 ms P50)—zero LLM calls, zero hallucinations
Fixes Markdown fences, // and /* */ comments, unquoted keys, single quotes, Python True/False/None, and trailing commas
Closes truncated strings, arrays, and objects when an LLM hits max_tokens mid-stream

Production API Integration

Automate This Check in Your Backend or CI/CD Pipeline

This browser tool runs on the exact same stateless Cloudflare Worker microservice as our production APIs. Subscribe on RapidAPI or Zyla API Hub to unlock up to 256 KB payloads and 500,000 monthly requests:

🩹 POST /v1/json-heal Live on Hub

Broken JSON & LLM Output Healer API

Repair malformed or truncated LLM JSON outputs into valid, schema-checked JSON in 1 ms.

Live Sample & Docs → OpenAPI

Get API Key on RapidAPI Get API Key on Zyla Hub View Full API Documentation →