Understand JSON Validation Errors

Introduction

Invalid JSON can break applications. Understanding standard errors is key to fast debugging.

Common Issues

1. **Trailing Commas:** JSON standard (RFC 8259) forbids commas after the last element.

- *Bad:* `{ "a": 1, }`

- *Good:* `{ "a": 1 }`

2. **Unquoted Keys:** All keys must be strings in double quotes.

- *Bad:* `{ key: "value" }`

- *Good:* `{ "key": "value" }`

3. **Mismatched Brackets:** Every opening `{` or `[` must have a matching closing one.

Using the Validator

Paste your code into the tool below. It will highlight the exact line and column of compliance errors so you can fix them immediately.

Interactive Demo: VALIDATOR

Your JSON

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Interactive Tree

Valid

{5 Itemsname: "JSON Buddy Tools"
description: "Privacy-first JSON formatter with advanced features"
features: []7 Items
privacy: {}4 Items
shortcuts: {}3 Items
}

Output

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Frequently Asked Questions

How do I fix a trailing comma?

Simply remove the comma after the last item in an object or array.

What is an unquoted key?

It's a key name without double quotes found in JavaScript objects but invalid in strict JSON.

Does the validator auto-fix errors?

Yes, our tool often suggests or applies fixes for common syntax mistakes.