JSON Formatter & Validator
Format, beautify, minify and validate JSON online instantly. Detect invalid JSON, organise nested data and create clean, readable JSON directly in your browser.
Format & Validate JSON
Paste JSON below to format, minify or validate it instantly. Everything is processed directly in your browser.
JSON Statistics
A quick overview of the JSON currently being processed.
Characters
0
Bytes
0
Lines
0
Objects
0
Arrays
0
Private Browser-Based JSON Processing
Your JSON is processed directly inside your browser for normal formatting, minification and validation.
- No file upload is required.
- Formatting happens instantly on your device.
- JSON content does not need to be sent to SwiftVecto's server.
- You can copy the result or generate a JSON download directly from your browser.
JSON Quick Reference
A few common JSON syntax rules to remember when validation fails.
Valid JSON
{
"name": "SwiftVecto",
"active": true,
"tools": [
"JSON Formatter",
"JWT Decoder"
]
}Common Problems
- × Single quotes instead of double quotes.
- × Trailing commas after the final value.
- × Missing commas between properties.
- × Unquoted object property names.
- × JavaScript values such as undefined.
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How to Format and Validate JSON
Use the SwiftVecto JSON Formatter & Validator to beautify, minify and validate JSON data instantly. Paste JSON from an API response, application configuration, database export or development project and turn difficult-to-read data into clean, structured JSON while checking that the syntax is valid.
Overview
JSON, or JavaScript Object Notation, is one of the most widely used formats for exchanging structured data between applications, websites, APIs and services. JSON is designed to be both machine-readable and relatively easy for people to understand, but large or minified JSON documents can quickly become difficult to inspect. A missing comma, incorrect quotation mark or unmatched bracket can also prevent an application from parsing the data. This JSON Formatter & Validator provides developers, testers, system administrators, students and other technical users with a convenient way to inspect JSON, apply consistent indentation, remove unnecessary whitespace and identify invalid syntax. Processing can be performed directly in the browser, helping keep development data private while providing immediate results.
Benefits
How It Works
Paste or type JSON into the input editor.
The tool parses the supplied text according to JSON syntax rules.
If the JSON is valid, the parsed structure can be converted back into consistently formatted JSON.
Formatting adds indentation and line breaks without changing the underlying JSON values.
Minification performs the opposite operation by removing formatting whitespace and producing compact JSON.
Validation checks whether the supplied text can be parsed as a valid JSON value.
Objects can optionally have their property names sorted alphabetically while arrays retain their original item order.
The tool can calculate useful information such as characters, bytes, lines, objects and arrays contained in the JSON.
Formatted output can then be copied or saved as a JSON file for use elsewhere.
The interactive version of the tool performs normal formatting and validation directly in the browser for immediate feedback.
How to Use This Tool
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1Paste your JSON into the input area.
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2Choose your preferred indentation style, such as two spaces, four spaces or tabs.
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3Enable key sorting if you want object property names arranged alphabetically.
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4Select Format to beautify and organise valid JSON.
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5Select Validate when you only need to check whether the JSON syntax is valid.
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6Select Minify when you want to remove formatting whitespace and create compact JSON.
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7Review any validation message if the supplied JSON contains an error.
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8Inspect the formatted output and JSON statistics.
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9Copy the result to your clipboard or download it as a .json file.
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10Use Clear to reset the tool and begin with another JSON document.
Helpful Tips
- JSON object property names must normally be enclosed in double quotation marks.
- JSON strings use double quotes rather than single quotes.
- Do not place a trailing comma after the final property in an object or the final value in an array.
- Use two-space indentation when you want more compact readable output.
- Use four-space indentation when maximum readability is more important than vertical space.
- Minify JSON when whitespace is unnecessary, such as when embedding static JSON in an application.
- Keep formatted JSON during development because nested structures are much easier to inspect and debug.
- Validate API responses before assuming an application bug is caused by your own code.
- Use key sorting when comparing two JSON objects whose properties appear in different orders.
- Remember that sorting object keys should not be used when another system incorrectly relies on property order.
- Arrays are ordered collections, so their item order should generally be preserved.
- Be careful when manually editing escaped quotation marks and backslashes inside JSON strings.
- Use null for an intentional empty JSON value rather than undefined, which is not a JSON value.
- Large integers may require special handling in some programming languages because of numeric precision limitations.
- Avoid pasting passwords, API secrets or other unnecessary sensitive credentials into any tool, even when processing is local.
Common Uses
Beautify a minified REST API response.
Validate JSON before sending a request to an API endpoint.
Format application configuration data for easier editing.
Check JSON copied from browser developer tools.
Minify JSON before embedding it inside an application.
Inspect a webhook request or response payload.
Format JSON exported from a database or software service.
Validate sample JSON used in API documentation.
Clean up JSON generated by a script or development tool.
Format nested JSON objects before sharing them with another developer.
Check whether an invalid API request is caused by malformed JSON.
Sort object keys to make two JSON structures easier to compare manually.
Worked Examples
The following examples demonstrate how this tool can be used in realistic scenarios.
Formatting a Minified API Response
An API returns {"user":{"id":42,"name":"Michael","active":true},"roles":["admin","editor"]}. Paste the response into the formatter and choose Format. The same values are displayed across multiple indented lines, making the nested user object and roles array much easier to inspect.
Finding Invalid JSON
A developer receives {"name":"SwiftVecto","active":true,} and an application refuses to parse it. Validation identifies that the JSON is malformed because JSON does not allow the trailing comma after the final property.
Minifying Configuration Data
A formatted JSON configuration file contains many line breaks and indentation spaces. Selecting Minify removes unnecessary formatting whitespace while preserving the same objects, arrays and values, producing a smaller compact representation.
Reviewing Nested Data
A webhook contains customer information, an order object and an array of purchased items. Formatting the payload makes each hierarchy level visible, allowing the developer to find the required property without manually navigating a single long line of JSON.
Sorting Object Keys
Two configuration objects contain the same property names but list them in different orders. Enabling object key sorting arranges their keys alphabetically, making manual comparison easier while leaving array values in their original order.
Common Mistakes
Avoid these common mistakes to achieve the most accurate results.
- Using single quotation marks around JSON property names or strings instead of double quotation marks.
- Leaving a trailing comma after the final property in an object.
- Leaving a trailing comma after the final item in an array.
- Forgetting a comma between two object properties or array items.
- Using undefined as a JSON value. Valid JSON supports null but not JavaScript undefined.
- Adding comments such as // comment or /* comment */ to standard JSON.
- Forgetting to escape quotation marks contained inside a JSON string.
- Using an unquoted property name such as {name:"SwiftVecto"} instead of {"name":"SwiftVecto"}.
- Confusing a JavaScript object literal with strict JSON syntax.
- Accidentally removing an opening or closing brace from a nested object.
- Accidentally removing an opening or closing square bracket from an array.
- Assuming formatting invalid JSON will automatically repair ambiguous syntax errors.
- Changing array order while attempting to sort JSON data.
- Sharing JSON containing API keys, access tokens, passwords or personal information unnecessarily.
Glossary
Definitions of the most important terms used by this tool.
JSON
JavaScript Object Notation, a text-based data format commonly used to store and exchange structured information between applications.
JSON Object
A collection of named properties enclosed in curly braces. Each property consists of a key and a corresponding value.
JSON Array
An ordered collection of values enclosed in square brackets. Array values may include objects, other arrays, strings, numbers, booleans or null.
JSON Property
A key-value pair contained inside a JSON object. Property names are represented as JSON strings.
JSON Value
Data stored in JSON. Valid value types include strings, numbers, objects, arrays, booleans and null.
Formatter
A tool that restructures source text using consistent whitespace, indentation and line breaks to improve readability.
Beautify
To convert compact or poorly formatted JSON into an indented, human-readable representation.
Pretty Print
Another term commonly used for displaying JSON with indentation and line breaks so its structure is easier to understand.
Minify
To remove unnecessary formatting whitespace and line breaks while preserving the underlying JSON data.
Validation
The process of checking whether JSON conforms to the required syntax and can be successfully parsed.
Parser
Software that reads JSON text and converts it into a structured representation that an application can work with.
Syntax Error
An error caused when JSON does not follow the required grammar, such as a missing comma, invalid quotation mark or unmatched bracket.
Indentation
Whitespace placed before nested JSON properties and values to visually represent their position within the data structure.
Nested JSON
JSON where objects or arrays contain additional objects or arrays at deeper levels of the structure.
Escaping
Representing characters with special meaning using escape sequences so they can safely appear inside JSON strings.
REST API
A common style of web API where JSON is frequently used to send requests and return structured responses between systems.
Frequently Asked Questions
What is a JSON formatter?
A JSON formatter takes valid JSON data and applies consistent indentation and line breaks so objects, arrays and nested values are easier for people to read and understand.
What is a JSON validator?
A JSON validator checks whether supplied text follows valid JSON syntax. It can help identify problems such as missing commas, invalid quotation marks, trailing commas and unmatched brackets.
Does formatting JSON change the data?
Normal formatting changes whitespace and indentation but does not change the underlying values. If optional object key sorting is enabled, the order in which object properties are displayed may change, but array item order is preserved.
What does minifying JSON do?
Minifying removes unnecessary spaces, indentation and line breaks from valid JSON. The resulting JSON contains the same data but uses a more compact representation.
Is minified JSON still valid JSON?
Yes. Whitespace used for formatting is generally optional between JSON tokens, so valid JSON remains valid when unnecessary formatting whitespace is removed.
Why is my JSON invalid?
Common causes include missing commas, trailing commas, single quotes, unquoted property names, unescaped quotation marks, unmatched braces or brackets, comments and unsupported JavaScript values such as undefined.
Can JSON contain comments?
Standard JSON does not support comments. Text using JavaScript-style // comments or /* comments */ must normally have those comments removed before it can be parsed as standard JSON.
Can JSON use single quotes?
No. JSON strings and object property names use double quotation marks. Single quotes are accepted in some programming language syntax but are not valid standard JSON string delimiters.
Can JSON contain trailing commas?
No. Standard JSON does not permit a comma after the final property of an object or the final item of an array.
What values can JSON contain?
JSON supports strings, numbers, objects, arrays, true, false and null. JavaScript-specific values such as undefined, NaN and Infinity are not standard JSON values.
What indentation should I use for JSON?
Two spaces and four spaces are both common choices. Two spaces produce more compact output, while four spaces can make deeply nested data easier to read. The choice normally depends on your project or team coding style.
Does JSON object property order matter?
Applications should generally treat object properties as named values rather than depend on their displayed order. Arrays are different because array item order is significant and should be preserved.
What is the difference between JSON and a JavaScript object?
JSON is a text data format with stricter syntax rules. JavaScript object literals can use features that JSON does not allow, such as unquoted property names, methods and certain JavaScript-specific values.
Can I use this tool for API responses?
Yes. Formatting REST API responses, webhook payloads and other JSON-based service responses is one of the most common uses for a JSON formatter.
Can I minify an API request body?
Yes. Provided the JSON is valid, unnecessary formatting whitespace can be removed before the data is sent. Most APIs treat formatted and minified JSON equivalently.
Does SwiftVecto upload my JSON to the server?
The interactive JSON formatter is designed to perform normal formatting, minification and validation directly in your browser. This means the JSON does not need to be uploaded as a file for ordinary use of the tool.
Can I download the formatted JSON?
Yes. The tool interface can create a .json file from the formatted output so it can be saved and used in your project.
Can the formatter automatically repair invalid JSON?
The formatter is designed to identify invalid JSON rather than make potentially unsafe assumptions about what malformed data was intended to contain. Correct the reported syntax problem and validate the JSON again.
Can JSON contain nested objects and arrays?
Yes. Objects can contain arrays and other objects, while arrays can contain objects, arrays and other valid JSON values. The formatter is particularly useful for making deeply nested structures easier to inspect.
Is this JSON formatter free to use?
Yes. SwiftVecto provides the JSON Formatter & Validator as an online developer utility for formatting, minifying and validating JSON.
Things to Know
- Formatting requires syntactically valid JSON.
- Minification removes unnecessary formatting whitespace but does not intentionally alter JSON values.
- Object key sorting changes the displayed order of properties but should not change their associated values.
- Array item order is preserved when object keys are sorted.
- JSON strings, numbers, booleans, null, arrays and objects are supported.
- Standard JSON does not support comments, trailing commas or undefined values.
- The browser interface is intended to perform routine JSON formatting and validation locally for immediate results.
- Downloaded output should use the .json file extension.
- Very large JSON documents may consume significant browser memory depending on the device being used.
- Developers should avoid unnecessarily placing passwords, private keys, access tokens or other sensitive credentials inside development utilities.
Disclaimer
This tool checks JSON syntax and formatting but does not determine whether the data is semantically correct for a particular application or API.
Valid JSON may still be rejected by an external service when required fields, data types or application-specific validation rules are not satisfied.
This tool does not perform JSON Schema validation. JSON Schema validation should be treated as a separate developer capability.
Formatting and validation should not be used as a substitute for appropriate application-level testing and input validation.
Users remain responsible for protecting confidential information, credentials and other sensitive development data.
Official References
The following official resources were used when developing this tool and are useful for further reading.
RFC 8259 - The JavaScript Object Notation (JSON) Data Interchange Format
https://www.rfc-editor.org/rfc/rfc8259
JSON.org - Introducing JSON
https://www.json.org/
PHP Manual - JSON Functions
https://www.php.net/manual/en/book.json.php
MDN Web Docs - JSON
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON