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JSON Formatter & Validator

Paste JSON to validate syntax, pretty-print it with indentation, or minify it for compact storage and transfer.

Tool workspace

Privacy note: this tool runs in your browser. Do not use any online service for secrets unless its privacy and security practices meet your needs.

About this tool

About JSON Formatter & Validator

The JSON Formatter and Validator takes raw JSON, checks whether it is valid and reformats it into a readable, indented structure. It can also minify JSON when you need a compact version for transmission or storage.

Developers use it to debug API responses, review configuration files and find syntax mistakes such as a missing comma or an unquoted key. If the JSON is invalid, the tool reports an error so you know where to look.

Minified JSON is hard to read and one missing comma breaks everything. The JSON Formatter and Validator pretty-prints data with consistent indentation and tells you whether it is valid, so you can find the error before it reaches your application.

Validation catches syntax problems such as trailing commas, single quotes and unquoted keys. It does not check whether the data makes sense for your program, so you still need to confirm that the fields and types are what your code expects.

Step by step

How to Use JSON Formatter & Validator

  1. 1
    Paste your JSONAdd the JSON text into the input area. It can be a response, a config file or a snippet.
  2. 2
    Format or validatePress format to indent the data, or validate to check whether it is correct.
  3. 3
    Fix any errorsIf an error is reported, correct the highlighted problem such as a missing comma or bracket.
  4. 4
    Copy the clean outputCopy the formatted or minified JSON and use it in your project.
Real-world use

Where JSON Formatter & Validator helps most

Debugging API responsesMake a long response readable so you can find the field you need.
Fixing config filesFind the misplaced comma or quote in a settings file.
Minifying for transportStrip whitespace to keep a payload small.
Learning the formatSee how objects, arrays and values fit together.
Get better results

Practical tips for JSON Formatter & Validator

  • Look at the line and position in the error message first.
  • Remember that JSON uses double quotes only, with no trailing commas.
  • Format data before reading it, and minify it again if size matters.
  • Remove secrets such as tokens before you paste data anywhere.
  • Validate again after every manual edit.

Common mistakes to avoid

  • Pasting JavaScript objects with single quotes and expecting them to validate.
  • Leaving a trailing comma after the last item.
  • Sharing formatted data that contains API keys or personal details.
Benefits

Why Use JSON Formatter & Validator

Instant validationFind syntax errors without running your whole application.
Readable outputIndented formatting makes nested objects easy to scan.
Minify optionCreate a compact version for smaller payloads.
Local processingYour JSON is processed in the browser rather than uploaded.

Good to know. This tool runs in your browser, so the text you enter is processed on your own device. Even so, avoid pasting real passwords or secrets into any online tool. See the Privacy Policy for details.

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Questions & answers

Frequently Asked Questions

What is JSON?
JSON is a lightweight text format for structured data made of objects, arrays, strings, numbers, booleans and null, used widely in web APIs.
What are common JSON mistakes?
Typical errors include trailing commas, single quotes instead of double quotes, unquoted keys and missing brackets.
What does formatting do?
Formatting adds line breaks and indentation so the structure is easy to read, without changing the data itself.
What is minifying JSON?
Minifying removes unnecessary whitespace to produce the smallest valid text, which is useful for transfer and storage.
Should I paste sensitive data here?
Processing happens locally, but you should still avoid pasting passwords, tokens or private customer data into any online tool.
Why does valid-looking JSON fail?
Small details such as invisible characters, comments or smart quotes copied from documents can make otherwise correct JSON invalid.