Format and Beautify JSON
Turn a long single-line JSON string into readable, indented text with 2 spaces, 4 spaces, or tabs. Switch to Tree view to expand and collapse nested objects and arrays.
JSON Formatter & Validator
Format, validate, minify and fix JSON online. Paste your JSON and get clean, highlighted output with clear error messages. Fast, free and no signup.
- 100% free
- No Signup
- Runs in your browser
Input JSON
Invalid JSON
0 characters · 0 lines
Output
Your formatted JSON appears here
Paste JSON on the left and it is formatted instantly.
Waiting for input
Your Privacy Matters
Your JSON never leaves your device. Everything happens in your browser, so nothing is uploaded.
How to format JSON online
1Paste your JSON
Paste text, drop a .json file, or upload one from your device.
2Choose your options
Format or minify, pick the indent size, and sort the keys if you like.
3Copy or download
Copy the clean result or download it as a .json file. Errors are shown with the exact line.
JSON FORMATTER GUIDE
JSON Formatter and Validator – Beautify, Minify and Fix JSON Online
Looking for a free JSON formatter? Paste your JSON and get clean, indented, color-highlighted output in an instant. The tool also works as a JSON validator that checks your syntax and shows the exact line and column of an error, a JSON minifier that removes all extra whitespace, and a quick fixer for the most common mistakes. Everything runs in your browser, so your data is never uploaded, and there is no signup.
Validate JSON with Clear Errors
See at once whether your JSON is valid. If it is not, the tool shows the error message with the line and column, and a Go to error button jumps straight to the problem.
Minify and Sort JSON
Remove every unnecessary space and line break to make JSON smaller for APIs and config files, or sort all keys alphabetically to compare two files more easily.
How to Format JSON Online
You do not need to install an editor plugin to read a block of JSON. Use the online JSON formatter by following these steps.
- Add your JSON: Paste it into the Input box, click Upload to choose a .json file, or drag and drop a file onto the box. Click Sample to try an example.
- Pick a mode: Choose Format to beautify the JSON, or Minify to compress it into a single line.
- Set the options: Choose 2 spaces, 4 spaces, or Tab for the indent, and turn on Sort keys A–Z if you want the keys in alphabetical order.
- Check the result: The output updates as you type. Use Code view for highlighted text or Tree view to explore nested data.
- Copy or download: Click Copy to copy the output, or Download to save it as a .json file.
If your JSON has an error, the tool tells you where it is. You can also click Try auto-fix to repair common problems such as trailing commas, single quotes, unquoted keys, and comments.
What Is JSON?
JSON (JavaScript Object Notation) is a lightweight text format for storing and exchanging data. It is easy for people to read and easy for programs to parse, which is why most web APIs, configuration files, and databases use it. A JSON value can be one of these types:
- Object: A set of key and value pairs inside curly braces, such as
{"name": "Ali"}. Keys must be strings in double quotes. - Array: An ordered list of values inside square brackets, such as
[1, 2, 3]. - String: Text in double quotes, such as
"hello". - Number: An integer or decimal number, such as
42or3.14. - Boolean and null: The values
true,false, andnull, written in lowercase.
Common JSON Errors and How to Fix Them
Most invalid JSON comes from a handful of small mistakes. The validator points to the spot, and these are the usual causes.
- Trailing comma: A comma after the last item in an object or array is not allowed in JSON. Remove it.
- Single quotes: Strings and keys must use double quotes, not single quotes.
- Unquoted keys: Every key must be wrapped in double quotes, even if it looks like a simple word.
- Comments: JSON does not support // or /* */ comments. Delete them before parsing.
- Missing or extra brackets: Every opening brace or bracket needs a matching closing one.
- Missing comma: Items in an object or array must be separated by commas.
Where to Use a JSON Formatter
- API development: Read and debug responses and request bodies.
- Configuration files: Clean up and check files such as package.json, tsconfig.json, and app settings.
- Data cleanup: Sort keys, minify payloads, and prepare data for sharing.
- Learning and teaching: Understand the structure of nested data with the tree view.
Free JSON Formatter Online
Our free JSON formatter makes it easy to beautify, validate, minify, and fix JSON without leaving your browser. It is designed for convenient everyday use without signup, and it works on desktop and on mobile browsers.
COMMON QUESTIONS
Frequently Asked Questions About the JSON Formatter
Find answers to common questions about formatting, validating, and minifying JSON.
How do I format JSON online?
Paste your JSON into the Input box. The tool formats it right away with the indent you chose, and the result appears in the Output box, ready to copy or download.
Is my JSON uploaded to a server?
No. Your JSON is processed inside your browser, and it is not uploaded or stored anywhere. When you close or refresh the page, the data is gone from the tool.
How does the JSON validator work?
The tool tries to parse your text as standard JSON. If it succeeds, it shows a Valid JSON badge with the size, the number of keys, and the depth. If it fails, it shows the error message and, when your browser provides it, the line and column.
How do I find the error in my JSON?
When your JSON is invalid, an error bar appears under the Input box. Click Go to error to jump to the position of the problem, then check for a missing comma, an extra comma, a missing quote, or an unmatched bracket near it.
What does Try auto-fix do?
It repairs common mistakes: it removes comments and trailing commas, changes single quotes to double quotes, adds quotes around unquoted keys, and converts Python-style True, False, and None to true, false, and null. It cannot fix every problem, so check the result if an error remains.
What is the difference between Format and Minify?
Format adds line breaks and indentation so that the JSON is easy to read. Minify removes all unnecessary whitespace and puts everything on one line, which makes the text smaller. The data itself stays the same.
What does Sort keys A–Z do?
It sorts the keys of every object in alphabetical order, including nested objects. This is handy when you want to compare two JSON files, because the same data always appears in the same order.
What is the Tree view?
Tree view shows your JSON as a collapsible outline. Click an object or array to open or close it, or use Expand and Collapse to change every level at once. It is useful for exploring large, deeply nested data.
How large a JSON file can I use?
You can upload a file of up to 10 MB. Very large input can be slow because everything runs in your browser, so syntax highlighting and Tree view are switched off automatically for big results, while formatting and copying still work.
Why did a very large number change after formatting?
Browsers read JSON numbers as standard floating-point numbers, which keep about 15 to 17 significant digits. An integer longer than that, such as a 20-digit ID, can lose precision. If you need to keep a long ID exact, store it as a string in quotes.
Is this JSON formatter free?
Yes. You can format, validate, minify, and fix JSON online for free, with no signup.
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