JSON Formatter and Validator
Format, minify, and validate your JSON data. Features a collapsible tree view and detailed error reporting.
What is the JSON Formatter and Validator?
Struggling with unformatted or minified JSON? Our formatter instantly cleans up messy data, making it readable and easy to debug. Paste your JSON to pretty-print it with your choice of indentation, or minify it to reduce size. Go beyond basic formatting with an interactive '๐ณ Tree' view to explore complex nested structures, and an option to 'Sort Keys (AโZ)' for a consistent order. If there's an error, we'll pinpoint the exact line and column. All processing happens in your browser, so your data stays private.
How to use
- Paste your JSON into the "JSON Input" box, or drag and drop a .json file onto the designated area.
- Click "Format (Pretty)" to make it human-readable, or "Minify" to compress it into a single line.
- The result appears on the right. For complex data, switch to the "๐ณ Tree" view to browse it as a collapsible structure.
- Customize the output using the "Indent" dropdown or by checking "Sort Keys (AโZ)". The result updates automatically.
- Click "Copy" to put the formatted/minified JSON on your clipboard, or "Save" to download it as a .json file.
- If your input has a syntax error, a message will immediately specify the error and its location by line and column.
JSON Formatter and Validator guide
How this tool is used in real work, and what to watch out for.
The 5 Most Common Causes of a "Broken JSON" Error
Most JSON syntax errors stem from a few common mistakes. This tool tells you the exact line and column number where an error was found, so by checking against this list, you can usually find the cause in seconds.
- Trailing comma after the last item โ JavaScript objects allow this, but it's an error in JSON. Check right before a closing bracket or brace.
- Using single quotes โ Strings and keys in JSON must use double quotes.
- Keys without quotes โ `{name: "John Smith"}` is not valid JSON. It must be `{"name": "John Smith"}`.
- Including comments โ The JSON standard has no comments. The presence of `//` or `/* */` will cause an error.
- Values are `undefined` or `NaN` โ These values don't exist in JSON. You must use `null` or omit the key entirely.
Understanding Deep Structures with the Tree View
For deeply nested JSON, like an API response, just formatting it isn't enough to see the whole structure at a glance. By switching to the ๐ณ Tree view in the result area, you can collapse and expand each node, letting you focus only on the branches you're interested in.
Next to each array, you'll see a count of its items, and next to each object, a count of its keys. This lets you instantly see how many records are in a response without having to count them one by one.
- Paste your JSON into the input box and click "Format (Pretty)".
- Select the "๐ณ Tree" tab above the result area.
- Click the triangle icons to expand only the branches you need.
- Check the stats at the bottom for total size, key count, max depth, and total nodes.
Format vs. Minify: When to Use Which
Formatting (Pretty) is for humans to read, while Minifying is for machines to process. The data in both is identical; only the whitespace differs.
| Scenario | Action | Reason |
|---|---|---|
| Visually inspecting an API response | Format | The hierarchy is visible, making it easy to see what's where. |
| Committing a config file to a repository | Format | Future changes (diffs) will be clean and line-by-line. |
| Sending as an HTTP request body | Minify | Reduces the transfer size by removing whitespace. |
| Storing in an environment variable or single-line field | Minify | Line breaks can cause the value to be truncated. |
When Is Sorting Keys Useful?
Checking "Sort Keys (AโZ)" reorders the keys of all objects alphabetically. This is especially useful when comparing two JSON objects. If you have two files with the same data but different key order, a diff tool might show the entire file as changed. By sorting the keys on both sides first, you can see only the real differences.
Handling Large Files
You can drag and drop a file or click the drop zone to select one. The file is read directly by your browser, meaning no upload occurs. This allows you to safely open sensitive data like internal company files or production logs.
However, since all processing happens in the browser, there are limits. Files up to several megabytes are handled fine, but files of tens of megabytes or more may cause the tree rendering to become slow. In such cases, it's better to use the ๐ Text view or switch to a command-line tool.
# Command line is faster for very large JSON
jq . big.json > pretty.json # Format
jq -c . big.json > small.json # MinifyFrequently asked questions
Is my JSON data sent to a server?
No. All formatting, validation, and analysis happen entirely within your browser. Nothing you paste is sent to a server, ensuring your data remains private and secure.
What makes this JSON formatter different?
It offers advanced features like an interactive "๐ณ Tree" view, an option to "Sort Keys (AโZ)", and a stats panel showing data "Size", "Key Count", and "Max Depth".
How does the JSON validation work?
If your input isn't valid JSON, an error message instantly points out the issue and its precise location by line and column number, helping you find and fix bugs fast.
Can it handle large JSON files?
Yes, it performs well with files up to several megabytes. You can load a file by dragging and dropping (max 8MB). For extremely large files, browser performance may vary.