Developer Playground
JSON Parser
Input JSON String and Parse Pretty Print Output.
Output
What is JSON?
JSON (JavaScript Object Notation) is a lightweight data-interchange format. It is easy for humans to read and write, and easy for machines to parse and generate. JSON is a text format that is completely language independent but uses conventions that are familiar to programmers of the C-family of languages, including C, C++, C#, Java, JavaScript, Perl, Python, and many others.
Supported JSON Data Types
Standard JSON supports the following six basic data types:
- String: A sequence of zero or more Unicode characters, wrapped in double quotes.
- Number: A signed decimal number that may contain a fractional part and use exponential E notation.
- Object: An unordered set of name/value pairs (keys must be strings).
- Array: An ordered collection of values.
- Boolean: Either
trueorfalse. - Null: An empty value, using the word
null.
JSON vs. XML: Why Choose JSON?
| Feature | JSON | XML |
|---|---|---|
| Readability | Higher (concise) | Lower (verbose) |
| Data Types | Strings, Numbers, Arrays | All data is Strings |
| Parsing Speed | Faster (Native JS support) | Slower |
How to use this JSON Parser
Paste your minified or unformatted JSON string into the Input area. Select your preferred indentation level (2, 4, or 8 spaces), and click Parse JSON. The formatted and color-coded JSON will be displayed in the Output area. If there are any syntax errors in your JSON, a helpful error message will be shown instead.
JSON Security Best Practices
When working with JSON in your own applications, follow these security guidelines:
- Never use eval(): To convert a JSON string into an object, always use
JSON.parse(). Usingeval()can execute malicious scripts embedded in the data. - Sanitize Inputs: Even if the data is valid JSON, validate the actual content before using it in database queries or UI rendering to prevent XSS.
- Secure Transmission: Always send JSON over HTTPS to prevent man-in-the-middle attacks from intercepting sensitive data.
Frequently Asked Questions (FAQ)
Can JSON have comments?
The official JSON standard (RFC 8259) does not support comments. However, some variants like JSONC (JSON with Comments) allow them, but standard parsers will throw an error.
What is the difference between JSON and a JavaScript Object?
JSON is a string format used for data transfer, while a JavaScript Object is a data structure in memory. JSON requires double quotes for keys and has stricter syntax rules.
Is there a size limit for JSON?
Theoretically, no. However, practical limits depend on the memory of the system parsing the JSON and the maximum string size of the language being used.