Smartweb.tools Free online JSON formatter. Format, beautify and validate JSON data instantly. Syntax errors are reported with the exact location. Browser-based.

Still loading the full interface. Please wait a moment.

JSON Formatter

Format and validate JSON data for developers and technical SEO work.

JSON formatter — format and validate JSON data online

The JSON Formatter parses your raw or minified JSON string and outputs it in a readable, indented format with proper line breaks and nesting. If the JSON contains a syntax error, the formatter shows the exact JavaScript error message so you can locate and fix the problem.

Formatted JSON is essential when debugging API responses, reviewing structured data markup in Google Search Console, reading webhook payloads, or checking configuration files before committing them to a repository.

Common JSON syntax errors

  • Missing commas: Between object properties or array items
  • Trailing commas: After the last property in an object or the last item in an array
  • Unquoted keys: Object keys must be wrapped in double quotes (not single quotes)
  • Single-quoted strings: JSON requires double quotes — single quotes are invalid
  • Missing closing brackets: Every { must have a matching } and every [ must have a ]

JSON in SEO

Google uses JSON-LD (Linked Data) in <script type="application/ld+json"> tags for structured data such as FAQPage, HowTo, BreadcrumbList, Product, and Article schema. Paste the raw JSON-LD from your page source to verify its structure before submitting to Google's Rich Results Test.

How to use JSON Formatter

  1. Paste your raw or minified JSON string into the text area.
  2. Click Format JSON.
  3. The formatted, indented output appears below — review the structure to understand nested objects and arrays.
  4. If there is a syntax error, the error message pinpoints the problem location.

Why this tool is useful

  • Instantly reveals the structure of nested JSON objects and arrays.
  • Error messages identify exactly where a syntax problem is located.
  • Useful for debugging API responses, webhook payloads and config files.
  • Runs entirely in the browser — no JSON data leaves your device.

Example use cases

Debug a malformed API response from a third-party webhook. Inspect Google Structured Data (JSON-LD schema) from a page source before submitting to Search Console. Validate a package.json or tsconfig.json file before committing to a repository. Review a WooCommerce order webhook payload to understand the available data fields.

Frequently asked questions

Is this tool free to use?

Yes. Smartweb.tools tools are free to use without credits, payment or required membership.

Do I need to create an account?

No account is required for the public tools. Open a tool, add your input and use the result immediately.

Is my data stored?

Most browser tools are designed to process common inputs in your browser. If a tool or contact form requires submitted data, the page will explain what is needed and why.

Related tools

  • URL Slug Generator — Generate clean SEO-friendly slugs for blog posts, tools and landing pages.
  • Google SERP Simulator — Preview how your page title, description and URL appear in Google search results before publishing.
  • Open Graph Preview — Preview your Open Graph meta tags as Facebook, Twitter and LinkedIn social media share cards.
  • Schema Markup Generator — Generate JSON-LD schema markup for articles, FAQs, products, local businesses, breadcrumbs and how-to guides.
  • Readability Score Checker — Check your text readability with Flesch-Kincaid grade level, reading ease score and Gunning Fog index.
  • Meta Length Checker — Check if your page title and meta description are the optimal length in characters and pixels for Google search results.