Paste it. Mended.

Fixes trailing commas, single quotes, comments, code fences and cut-off output from ChatGPT, APIs and logs. Every fix is listed with its line. Your values are never changed.

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Output format

What it fixes

The usual suspects.

Trailing commas, single quotes, unquoted keys, comments, Python True and None, NaN, missing commas, missing brackets, a ```json fence, chatter around the JSON, and output cut off mid-value.

The promise

Syntax only, never data.

Strings and numbers stay exactly as written, including huge numbers and trailing zeros, and key order is kept. Asking a model to fix JSON can silently change values. Mend can not.

Private

Nothing leaves your device.

Everything runs in your browser. There is no account and your text is not uploaded.

Use Mend with your AI

Add Mend to ChatGPT, Claude, Cursor or any assistant that supports MCP, then ask it to repair broken or invalid JSON, find where it breaks, and outline or query large JSON. No key, no login.

https://mend.clawhard.com/mcp

Add to Cursor Add to VS Code Add to Claude

More ways to connect

Claude Code

claude mcp add --transport http clawhard-mend https://mend.clawhard.com/mcp

Codex

codex mcp add clawhard-mend --url https://mend.clawhard.com/mcp

Gemini CLI

gemini mcp add --transport http clawhard-mend https://mend.clawhard.com/mcp

Cursor, Windsurf and others (mcp.json)

{
  "mcpServers": {
    "clawhard-mend": { "url": "https://mend.clawhard.com/mcp" }
  }
}

ChatGPT

Open Plugins → Add → Add custom MCP server, paste the URL above, choose No authentication, then create it.

Other apps: Goose · LM Studio. Any MCP client works with the URL (Streamable HTTP, no headers).

OpenAPI (custom GPT Actions, scripts) · llms.txt · MCP server card · Agent card · All Clawhard tools in one connector

Common questions

Mend repairs broken JSON (trailing commas, single quotes, comments, Python literals, code fences, truncated output), tells you exactly where invalid JSON breaks, and outlines or queries big payloads. Runs in your browser, no account.

How do I fix "Unexpected token" in JSON.parse?

Paste the text into Mend. It finds the cause (often a trailing comma, single quotes, an unquoted key, a comment or text around the JSON), fixes it and shows each change with its line and column.

Why does JSON from ChatGPT or another LLM fail to parse?

Models often wrap JSON in a ```json fence, add a sentence before or after it, leave trailing commas, use single quotes or Python True/None, or stop mid-output when they hit a token limit. Mend handles all of these.

Does Mend change my data?

No. It only fixes syntax. Strings and numbers are kept as written, including very large numbers and trailing zeros, and key order is preserved unless you ask to sort keys.

What if my JSON was cut off?

Mend closes open strings, arrays and objects at the cut so the result parses, and warns that the last value may be incomplete.

Is my JSON uploaded anywhere?

No. The web page runs in your browser. The API and MCP tools process what you send to return the answer and do not store it.

Can an AI assistant use Mend?

Yes. Add the MCP server https://mend.clawhard.com/mcp (tools mend_repair_json, mend_check_json, mend_outline_json, mend_query_json) or call the JSON API described at /openapi.json.

For AI assistants and developers: llms.txt · API (OpenAPI) · MCP server · sitemap