XML to JSON & JSON to XML Converter

The XML to JSON and JSON to XML Converter is a fully client-side tool that transforms data between the two most widely used structured data formats. Powered by the fast-xml-parser library running entirely in your browser, it handles real-world documents including attributes, nested elements, repeated sibling tags, typed values, and XML declarations — without uploading a single byte to any server.

XML to JSON Conversion

When converting XML to JSON, the tool parses the full XML document tree and maps each element to a JSON key. XML attributes are preserved using a configurable prefix (default @_) so they remain distinguishable from child elements in the output. Repeated sibling elements with the same tag name are automatically collected into JSON arrays. Numeric and boolean text content is optionally parsed into their native JSON types rather than left as strings, producing cleaner output for downstream JavaScript consumers.

JSON to XML Conversion

When converting JSON to XML, the tool maps each JSON key to an XML element. Keys that begin with the configured attribute prefix are written as XML attributes on the parent element. Arrays are expanded into repeated sibling elements sharing the same tag name. If the JSON object has a single top-level key, that key becomes the root element; otherwise the document is wrapped in a configurable root element name. An optional XML declaration line (<?xml version="1.0" encoding="UTF-8"?>) can be prepended to the output.

Attribute Prefix Configuration

The attribute prefix controls how XML attributes are represented in JSON. The default @_ prefix is the fast-xml-parser convention and is unambiguous. The compact @ prefix is used by some libraries like BadgerFish and jxon. The verbose attr_ prefix is easier to read in plain text. Choose the prefix that matches the convention expected by your downstream parser or library.

Typed Value Parsing

When typed value parsing is enabled, the converter automatically coerces XML text content and attribute values to their native JSON types. The string "true" becomes the boolean true, "42" becomes the number 42, and "null" becomes null. Disable this option when you need all values preserved as strings, for example when processing data where numeric-looking strings like zip codes or phone numbers must not lose leading zeros.

Format Compatibility

The converter handles standard XML 1.0 documents including CDATA sections, processing instructions, and entity references. On the JSON side it accepts any valid JSON value — objects, arrays, strings, numbers, booleans, and null. The output XML is always well-formed and can be validated against an XSD schema or processed with XSLT. The output JSON is always valid and can be parsed by any standard JSON library in any programming language.

Performance on Large Files

Because all processing runs in the browser using optimised JavaScript, conversion is near-instant for files up to several megabytes. Very large documents (tens of megabytes) may take a few seconds depending on your device. There are no server-side upload limits, rate limits, or file size restrictions — the only practical ceiling is your browser tab's available memory.