Is JSON Formatter & Validator free to use?

Yes. JSON Formatter & Validator is free, has no usage cap and does not require an account. There is no paid tier that unlocks extra output.

Does my data get uploaded to a server?

No. The tool is a JavaScript function that runs inside your browser tab. Nothing you paste or drop in is transmitted, logged or stored by us.

Do I need to create an account?

No account, no email address and no sign-in. Open the page and start working.

Does it work on a phone or tablet?

Yes. The interface is responsive and works in mobile Chrome, Safari, Edge, Firefox and Samsung Internet. You can also install Toolspea as an app from the browser menu.

Can I use the output commercially?

Yes. You keep every right you already had over the input, and we claim nothing over the output.

Why does my JSON fail validation when it looks correct?

The three most common causes are a trailing comma after the final item, single quotes instead of double quotes around keys or strings, and an unescaped newline inside a string. The error message gives the character position of the first failure.

Does formatting change my data?

No. The tool parses to an in-memory structure and re-serialises it. Values, types and array order are preserved; only whitespace, and key order if you enable sorting, change.

Can I paste JSON containing credentials?

The parsing happens locally in your browser and nothing is transmitted, but the safest habit is still to redact secrets before pasting into any tool.

What is the difference between JSON and JSON5?

JSON5 permits comments, trailing commas, unquoted keys and single quotes. This validator implements strict RFC 8259 JSON, which is what JSON.parse and most APIs accept.

Developer tools

JSON Formatter & Validator

Pretty-print, minify and validate JSON with precise error positions.

JSON input

Result

Options

Output

Indent spaces

Sort object keys alphabetically

Everything above is processed in this browser tab. Your input is never sent to a server.

What is JSON Formatter & Validator?

JSON Formatter & Validator parses a JSON string, reports syntax errors with their character position, and re-serialises the data either indented for reading or minified for transport. It is used to make an API response legible, to check a config file before deploying, and to shrink payloads.

How to use it

1Paste raw JSON — minified, escaped or hand-edited.
2Choose pretty-print or minify and set the indent width.
3If the JSON is invalid, the error message names the position of the first problem.
4Copy the formatted output back into your editor or request body.

Features

Strict JSON parsing with human-readable error positions
Configurable indentation from one to eight spaces
Optional alphabetical key sorting for stable diffs between environments
Minify mode strips all insignificant whitespace

When people use it

Debugging an API response

A minified response in a network tab is unreadable. Pretty-printing reveals nesting depth and makes a missing field obvious.

Stabilising config diffs

Sorting keys before committing means version control shows real changes rather than reordering noise.

Validating before deploy

A trailing comma in a config file can break a deployment. Validating locally catches it in seconds.

Known limits

Strict JSON only: comments, trailing commas and single-quoted strings are rejected by design, matching JSON.parse.