JSON Formatter
Runs locally in your browser. Inputs are not sent to a server.Converts in real time, no separate process button needed.Validate, format, minify, analyze, and inspect JSON as a tree locally.
How it works
Video
Step by step
- 1
Choose a mode
Choose between pretty print for readable JSON and minify for the smallest possible file size.
- 2
Paste your JSON
Paste JSON text, drop a file via drag and drop, or choose one via “browse”.
- 3
Review the result
View the result as formatted text or as an interactive tree; adjust advanced settings if needed.
- 4
Copy or download
Copy the result to the clipboard or download it as a .json file.
Good to know
The JSON Formatter formats, minifies, and analyzes JSON directly in your browser. It is especially useful when API responses, configuration files, webhook payloads, or log output need to become readable quickly. Instead of checking dense JSON blocks manually, the tool shows syntax errors, duplicate keys, and structured output immediately.
Valid JSON consists of objects, arrays, strings, numbers, booleans, and null. A missing comma, an extra quote, or a disallowed comment can be enough for an API or application to reject a payload. The formatter helps validate, beautify, minify, and inspect JSON data without sending content to a server.
Typical use cases
Debug API responses
Format compact JSON responses from REST APIs, webhooks, or browser developer tools to understand fields, arrays, and nested objects faster.
Prepare JSON for reviews
Use pretty print, indentation, and optionally sorted keys so JSON configuration can be reviewed more easily in pull requests and documentation.
Inspect production data locally
Inspect sensitive sample payloads, log fragments, or internal configuration locally in the browser without uploading them to external JSON online services.
Tips for better results
Read the error message first
When JSON is invalid, the issue is often just before the reported position: a missing comma, wrong quotes, trailing comma, or a comment.
Use minify mainly for delivery
Minified JSON saves space but is harder to read. For debugging and code review, formatted JSON with stable indentation is usually better.
Features
Pretty print and minify
Format JSON with readable indentation, or minify it down to the smallest possible size.
Live validation with precise error messages
Syntax errors and duplicate keys are detected as you type, with a clear, specific error message.
Interactive tree view
Alongside the formatted text view, the same structure can be explored as a navigable tree with object and array summaries.
Configurable formatting
Indentation (2, 3, 4 spaces or tab), line endings (LF/CRLF), key sorting, and non-ASCII escaping can each be configured individually.
Up to 50 MB, no upload
JSON files up to 50 MB are processed entirely in your browser. There is no server round trip.
Copy or download the result
The formatted or minified result can be copied to the clipboard or downloaded as a file with one click.
Frequently asked questions
Is the JSON Formatter free?
Yes. The JSON Formatter is completely free to use, with no sign-up and no usage limit.
Are my JSON files uploaded anywhere?
No. All processing happens locally in your browser. Pasted text and selected files are never sent to a server.
How large can the JSON file be?
Up to 50 MB per file.
What is the difference between pretty print and minify?
Pretty print adds indentation and line breaks for readability. Minify removes all non-essential whitespace to make the file as small as possible.
Does the tool detect duplicate keys or invalid JSON?
Yes. For duplicate keys and syntax errors, the tool shows a precise error message instead of silently changing the result.
Can I see a tree structure instead of the formatted view?
Yes. The “Tree” tab in the output shows the same structure as a navigable tree with object and array summaries.
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