JSON Formatter

Format, validate and minify JSON instantly in your browser — no data sent to a server.

How to use the JSON Formatter

  1. Paste your JSON. Drop raw or mangled JSON into the input box — it can be a single object, an array, or any valid JSON structure.
  2. Choose an action. Click Format / Beautify to make it readable, Minify to compact it, or Validate to check it without changing the output.
  3. Copy the result. Use the Copy button to grab the formatted output and paste it into your editor, terminal or API client.

Why use our JSON Formatter

Instant formatting and validation. Paste any JSON and hit Format — errors are caught immediately and the exact parser message is shown so you can fix problems fast.
Minify for production. Strip all whitespace to produce the smallest possible JSON payload — ideal for APIs, configs and embedded data.
100% private. All processing happens in your browser using the built-in JSON engine. Nothing you paste is ever sent to a server.

Free to use — premium coming soon

FREE
  • Format / beautify
  • Minify
  • Validate with error detail
  • Configurable indent
PREMIUM
  • Remove ads
  • Format JSON files by upload
  • Save and compare snapshots

About the JSON Formatter

JSON Formatter takes a raw, single-line blob of JSON and turns it into clean, indented text you can actually read. Paste an API response, a config file, or a log line and the tool pretty-prints it with consistent indentation and line breaks so nested objects and arrays line up visually. The same tool runs in reverse too: minify strips every non-essential space and newline to shrink payloads for production, and validate parses the text against the JSON grammar so you know whether it is well-formed before you ship it anywhere.

Reach for it whenever JSON arrives in a state you cannot read. The classic case is debugging: you copy a response body out of browser DevTools, a curl command, or an API client, and it lands as one unbroken line hundreds of characters wide. Beautifying it reveals the structure instantly. Minifying is the opposite need, useful when you are pasting a value into a single-line config field, an environment variable, or a request body where whitespace wastes bytes. Validation matters most when you have hand-edited a file and need to confirm you did not break the syntax.

Under the hood the formatter parses your text into an in-memory tree of objects, arrays, strings, numbers, booleans and null, then serializes that tree back out with your chosen indentation. Because it follows the JSON grammar from RFC 8259, it rejects the things that look fine in JavaScript but are not legal JSON: trailing commas, single-quoted strings, unquoted keys, and // or /* */ comments. When parsing fails, the tool reports the line and column of the offending character with a short description, so you can jump straight to the comma or brace that is out of place.

Everything happens in your browser. Your JSON is parsed and reformatted entirely on your own device with client-side JavaScript, so the text is never uploaded to a server, logged, or stored. That makes it safe to paste payloads that contain internal IDs, tokens, or other sensitive fields. Note that the validator checks syntax, not meaning: it confirms your JSON is structurally legal, but it cannot tell you whether a field name is spelled the way your API expects or whether a value falls in an allowed range. For that you need a JSON Schema validator, which is a separate step.

Frequently asked questions

Why does my JSON say invalid when it looks correct?

The most common culprits are a trailing comma after the last item in an object or array, single quotes instead of double quotes, or unquoted keys. JSON also forbids comments, so any // or /* */ left over from copied JavaScript will fail. The error message points to the line and column where parsing stopped.

What is the difference between beautify and minify?

Beautify (format) adds indentation and line breaks so the JSON is easy to read and review. Minify removes all unnecessary whitespace to make the file as small as possible, which is useful for production payloads and storage. The data is identical either way; only the spacing changes.

Is my JSON sent to a server?

No. The tool parses and formats your JSON entirely in your browser with JavaScript, so nothing is uploaded, logged, or stored. You can safely paste data that contains internal identifiers or tokens.

Can it fix or repair broken JSON automatically?

This tool validates and reports exactly where the JSON is invalid so you can correct it, rather than silently guessing at a fix. It does not auto-repair, because automatically removing a comma or changing a quote can change meaning; you stay in control of the edit.

Does JSON allow comments or trailing commas?

No. Standard JSON as defined by RFC 8259 has no comment syntax and does not permit a comma after the final element of an object or array. Formats like JSONC or JSON5 add those features, but they are not valid in plain JSON and most strict parsers will reject them.

From our blog

Which Text Case Should You Use? A Practical Guide for Writers and Developers

By the Super Simple Digital Tools Team · Updated June 2026

Capitalization is not just cosmetic. The case you choose signals context: a marketing headline in Title Case looks authoritative, the same words in all caps read as shouting, and a database field written in Title Case will simply break a query. Picking the right case is about matching the convention your reader, your style guide, or your programming language expects. Once you know which convention applies, converting text to match it should take a single click rather than a careful retype.

For everyday writing, two cases cover most needs. Sentence case is the default for body text, emails, captions and UI microcopy because it reads naturally and is easy to scan. Title Case is reserved for headlines, article titles, book and product names, and table headings. If you have inherited text that arrived in ALL CAPS, the fastest fix is to convert it to lowercase first and then apply Sentence or Title case, which clears out the original capitalization cleanly before reapplying the rule you want.

Developers face a different set of conventions, and mixing them causes real bugs. camelCase is the norm for variables and functions in JavaScript, TypeScript and Java. snake_case is expected for Python identifiers and is the safe choice for SQL column names because it avoids spaces and case-sensitivity surprises. kebab-case is the standard for CSS class names and for URL slugs, where hyphens are preferred over underscores for readability and SEO. PascalCase, a camelCase variant that also capitalises the first word, is typically reserved for class and component names.

The reason consistency matters so much in code is that many systems are case-sensitive. A variable called userId is a different name from UserID or user_id, and a typo'd casing produces an undefined value rather than an obvious error. Likewise, URLs and class names with stray capitals or spaces can fail silently. Converting an entire list of identifiers to one convention in a single pass removes that whole category of mistake and keeps a project readable for the next person who opens it.

The workflow is the same regardless of which case you need: paste the text, choose the target case, copy the result. Because the conversion is rule-based, it scales just as easily to a hundred lines as to one. The only thing the tool cannot decide for you is intent around proper nouns and acronyms, so for headlines and names give the output a final glance. With that one habit, a case converter turns a tedious manual chore into a reliable, repeatable step in your writing or coding routine.

  • To fix text stuck in ALL CAPS, convert to lowercase first, then apply Title or Sentence case so the original capitals do not survive.
  • Use snake_case for database and Python identifiers, but switch to kebab-case for URLs and CSS class names, where hyphens are the expected separator.
  • After running Title Case on a headline, scan for proper nouns, brand names and acronyms like NASA or iPhone, which automatic rules may not capitalise correctly.
  • Pick one style guide for Title Case and stick with it, since AP capitalises four-letter prepositions while Chicago keeps most prepositions lowercase, producing slightly different results.

Read the full guide →

Tool by the Super Simple Digital Tools Team. Reviewed by our editorial team. Free to use, no signup required.

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