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JSON formatter, minifier and validator

Format, beautify or minify JSON — with instant validation.

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This free JSON formatter beautifies, minifies and validates JSON instantly. Paste messy or minified JSON and get clean, indented output that's easy to read and debug — or minify it to save space. Invalid JSON is flagged so you can fix it fast. Nothing is uploaded.

How to use it

  1. Paste your JSON into the editor.
  2. Choose Format to beautify or Minify to compact it.
  3. Copy the clean, valid result.

Frequently asked questions

What is JSON?

JSON (JavaScript Object Notation) is a lightweight, text-based data format used by most web APIs to exchange structured data between systems.

What does formatting (beautifying) do?

It adds consistent indentation and line breaks so nested objects and arrays are easy to read, without changing the data.

Why is my JSON invalid?

The most common causes are trailing commas, single quotes instead of double quotes, missing brackets, or comments — which JSON doesn't allow.

What is JSON formatter, minifier and validator?

Format, beautify or minify JSON — with instant validation.

When would I actually use this?

Making a machine-generated blob readable, finding the character where a parse fails, and shrinking a file before it ships.

What is the most common mistake?

Assuming valid means correct. A document can parse cleanly and still have the wrong shape for whatever will read it — validation checks the syntax, not the schema.

How is JSON formatter, minifier and validator different from XML Formatter / Validator?

They sit next to each other but answer different questions. XML Formatter / Validator: pretty-print, minify and check whether XML is well-formed, all in your browser. Pick whichever matches what you're starting from — both are free.

Is there a tool for the next step?

YAML Formatter / Validator is the closest one after this: Tidy YAML — normalize indentation, convert tabs to spaces and flag tab-indent errors.

What else is worth having open alongside it?

CSS minifier and JavaScript Minifier / Beautifier — they come up in the same task often enough to be worth a second tab.

Where do the figures come from?

Parsing and serialisation follow each format's specification. Key order and whitespace are not semantically meaningful in JSON or YAML, so a reformatted document is equivalent even when the bytes differ.

Further reading

All guides →
ComparisonJSON vs XML: What's the Difference?JSON and XML both store structured data as text, but they trade off differently. Here's how each looks, where each wins, and how to choose.ExplainerXML to JSON: Attributes, Repetition, and the Single-Element Array TrapTwo documents that differ only in how many children exist produce two different JSON shapes, and no converter can tell them apart without a schema. Plus what this one really does with attributes, mixed content and whitespace — and the one thing it still cannot record.How-toHow to Convert JSON to CSV: Flattening Arrays of Objects into Rows and ColumnsA practical guide to turning a JSON array of objects into a clean CSV file, including how to flatten nested fields and handle the tricky edge cases.ExplainerEscaping a String for JSON: Three Characters Are Mandatory, and One Is a TrapRFC 8259 requires exactly three things to be escaped inside a JSON string. Everything else is optional. The one that actually breaks pipelines is a lone surrogate — legal in JSON text, impossible in UTF-8, and silently replaced the moment your data is written out.ExplainerWhat Is Base64 Encoding?Base64 turns binary data into safe text. Here's what it does, why it exists, why it isn't encryption, and the size cost it adds.How-toRegex Basics: A Beginner's GuideA regular expression is a pattern for matching text. Here are the building blocks — character classes, quantifiers and anchors — with a worked example.