🩹 n8n JSON Repair Tool

Free JSON Fixer for n8n Invalid JSON Errors

Fix malformed JSON instantly and understand what went wrong.

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What Causes Invalid JSON Errors in n8n?

Invalid JSON errors in n8n typically occur in HTTP Request nodes, Code nodes, or when parsing API responses. Common causes include missing quotes around strings, trailing commas, unescaped special characters, or expressions that resolve to [object Object] instead of actual values. The Set/Edit Fields node in JSON mode is particularly prone to these issues.

Why JSON Errors Are So Common in n8n

n8n workflows frequently handle JSON data from APIs, webhooks, and databases. When combining dynamic expressions with static JSON structures, it's easy to create invalid syntax. The error messages like 'The JSON Output contains invalid JSON' don't tell you WHERE the problem is. This tool pinpoints the exact issue and fixes it.

Avoiding JSON Errors in n8n

Use the Set node instead of Code node for simple data transformations
When using JSON mode, wrap the entire structure in double curly brackets
Avoid special characters like $& in expressions (known bug)
Use JSON.parse() and JSON.stringify() in Code nodes for safety
Test API responses with a temporary Set node to inspect the structure
Use a JSON validator before pasting into n8n

Frequently Asked Questions

What types of JSON errors can this tool fix?

The tool fixes common JSON issues including trailing commas, missing quotes around keys, single quotes instead of double quotes, undefined/NaN values (not valid JSON), unescaped special characters, and missing brackets. It handles most malformed JSON from n8n nodes.

Will fixing the JSON change my data?

The fixer preserves your data structure and values. It only fixes syntax issues. For example, undefined becomes null, trailing commas are removed, and quotes are corrected. The tool shows you exactly what changed so you can verify before using the fixed JSON.

Where do JSON errors typically occur in n8n?

Most JSON errors happen in HTTP Request body configurations, Set/Edit Fields nodes in JSON mode, Code node outputs, and webhook response bodies. The error 'The JSON Output contains invalid JSON' is especially common in Code nodes.

Can I paste partial JSON or just the broken part?

Yes, paste whatever you have. The tool attempts to fix both complete JSON objects and partial snippets. For best results, include the surrounding context so the fixer can understand the structure you're trying to create.

Is this tool free to use?

Yes, completely free with no signup required. We created this because JSON errors are frustrating and common in n8n. For help with complex data transformations or workflow development, we offer professional services.

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