JSON Formatter & Validator

Common JSON errors and how to fix them

Invalid JSON usually comes from small syntax issues that are easy to miss. The most common problems are trailing commas, single quotes instead of double quotes, missing quotes around keys, and unescaped line breaks inside strings. A validator highlights the error so you can correct it before an API call fails.

Format for readable reviews

Clean indentation makes large payloads easier to scan and debug. Formatting also helps when documenting APIs, writing examples for teammates, or storing JSON in config files where humans need to read and edit it.

Validate before sending requests

Valid JSON prevents 400 errors and failed deployments. When you are working with webhooks, config files, or API payloads, a quick validation step saves time. For larger workflows, pair this tool with the JSON to CSV Converter or compare outputs with the Text Diff Checker.

What Is a JSON Formatter and Validator?

A JSON formatter makes raw JSON easy to read by adding indentation and line breaks. A validator checks the syntax so you can spot errors before a request fails.

How It Works

Paste your JSON, then click Format or Validate. The tool runs locally in your browser and shows either clean output or a clear error message.

Benefits

• Readable indentation for quick review
• Immediate error feedback before you deploy
• Private processing with no uploads

Common Use Cases

• Debugging API responses and webhooks
• Cleaning config files and payloads
• Preparing examples for documentation

Frequently Asked Questions

Does formatting change my data? No. It only changes spacing and indentation.

Is the JSON uploaded anywhere? No. Everything runs locally in your browser.

Can it fix invalid JSON? It reports syntax errors so you can fix them.

What indentation does it use? The formatted output uses two-space indentation.

Related Tools

• Base64 Encoder/Decoder for encoding payloads
• Text Diff Checker for comparing JSON versions
• URL Encoder/Decoder for safe query strings