JSON Formatter, Viewer & Beautifier

When you actually need to format or validate JSON

Sometimes called a JSON viewer or JSON beautifier, this kind of tool shows up everywhere in SEO and web work — API responses, JSON-LD structured data, config files, sitemap-adjacent data feeds. JSON is also unforgiving: a single trailing comma or unescaped quote makes the entire file unreadable to whatever's trying to parse it, and the error messages browsers and APIs give you are often vague or point at the wrong line entirely.

This tool solves both halves of that problem — it reformats cramped or minified JSON into something readable (or the reverse, when you need to shrink a payload), and when something's actually broken, it walks the JSON grammar itself to tell you the exact line and column, instead of relying on whatever error message your browser happened to generate. If the JSON you're inspecting came from an HTML <script> tag or an API response, the HTML Formatter & Source Checker and Base64 Encoder / Decoder cover the two formats it's most often tangled up with.

For example, this minified line:

{"name":"Frost Rank","tools":4}

becomes:

{
  "name": "Frost Rank",
  "tools": 4
}

How to use this tool

1. 1
   Paste your JSON

   Paste the JSON into the input box, or click "Load example" to try the tool with sample data first.

2. 2
   Read the validation result

   The output updates as you type. Valid JSON is formatted straight away; invalid JSON shows an error with the exact line and column where parsing stopped.

3. 3
   Choose Beautify or Minify

   Beautify adds indentation and line breaks so the structure is easy to read. Minify strips every unnecessary space for the smallest possible payload.

4. 4
   Set the indent size

   When beautifying, switch between 2 spaces, 4 spaces or tabs to match the code style of the project you are pasting into.

5. 5
   Copy the result

   Click "Copy code" and paste the cleaned-up JSON back into your editor, API client or CMS.

Common use cases

• Reading an API response that arrives as one long unbroken line, so you can see how the objects nest and spot a missing field.
• Checking a JSON-LD block before it goes into a page template, since one syntax error makes search engines ignore the entire script.
• Tidying configuration files such as package.json or composer.json so code-review diffs stay readable.
• Minifying a payload for a request body, an HTML data attribute or an environment variable, where whitespace only adds bytes.
• Finding the one broken line in a large exported file that makes an import fail.

Tips and common mistakes

• Fix the first error, then re-check. A parser stops at the first problem it meets, so a single missing comma can hide other errors further down the file.
• Watch for JavaScript habits JSON forbids: single-quoted strings, unquoted keys, trailing commas, comments, and values like undefined or NaN are all invalid JSON.
• Strip wrappers before validating. JSON copied from a log line or an HTML attribute often carries escaped quotes (\") or surrounding text. If it arrived Base64-encoded, as in JWTs and some webhooks, decode it first with the Base64 Encoder / Decoder.
• Minified is not compressed. Minifying removes whitespace only; the data is identical. If you are writing structured data, the JSON-LD Schema Generator produces markup that is valid from the start. For the full grammar rules, read the JSON syntax and validation guide.

Frequently asked questions