Question 1

Why does my converted JSON have "@" and "#" symbols in the keys?

Accepted Answer

These symbols are artifacts of conversion conventions, most commonly the BadgerFish or Cobra conventions. Because JSON does not natively support XML attributes or text nodes mixed with elements, converters use special characters to represent them. The "@" symbol is used to denote that the key was originally an attribute in the XML (e.g., @id for id="123"). The "#" symbol, often #text, is used to hold the actual string content of an XML element when that element also contains attributes. This ensures no metadata is lost during the translation.

Question 2

How do I handle XML elements that only sometimes repeat, causing the "Single Array Element" bug?

Accepted Answer

To prevent a single XML element from being converted into a JSON object instead of a JSON array, you must use a converter that supports explicit type mapping or schema validation. You will need to provide a configuration file or a JSON path expression that explicitly tells the converter, "The element at path /users/role must always be output as an array, even if you only find one instance of it." If your converter lacks this feature, you must write custom post-processing middleware in your application to check the data type of the key and wrap it in an array [] if it is an object or string.

Question 3

Can I convert a 2GB XML file to JSON using standard tools?

Accepted Answer

Attempting to convert a 2GB XML file using standard DOM-based converters will almost certainly crash your system due to memory exhaustion, as the internal memory tree will require 10GB to 15GB of RAM. To handle files of this magnitude, you must use a stream-based (SAX) converter. A streaming converter reads the XML file sequentially from the hard drive, converts small chunks of data into JSON on the fly, and writes the JSON directly to an output stream. This approach keeps memory usage flat, typically under 50MB, regardless of the file size.

Question 4

Is it possible to convert JSON back to the exact same XML perfectly?

Accepted Answer

In most real-world scenarios, it is not possible to achieve a perfect, 100% identical round-trip conversion without specialized configurations. When XML is converted to JSON, structural nuances like the physical order of elements, XML namespaces, processing instructions (<?xml version="1.0"?>), and CDATA sections are often stripped or modified to fit JSON's simpler data model. Unless you use a strictly lossless convention like BadgerFish and ensure the JSON parser preserves key insertion order, converting the JSON back to XML will result in a document that contains the same core data but differs in structure and metadata.

Question 5

Why are all my numbers and booleans turning into strings in the JSON output?

Accepted Answer

In the XML standard, all data is represented as text. The XML tag 45.99 is just a string of characters; there is no metadata inherently telling the parser it is a floating-point number. A basic XML to JSON converter will play it safe and map everything to JSON strings, resulting in "price": "45.99". To get native JSON numbers and booleans, you must use a converter equipped with type inference (which uses regex to detect numbers and words like "true" or "false") or use a schema-aware converter that reads an XSD file to definitively know the required data types.

Question 6

What happens to XML namespaces during conversion?

Accepted Answer

The handling of XML namespaces (e.g., xmlns:soap="http://..." or ) depends entirely on the conversion convention you select. A strict convention will retain the namespace as a standard JSON key, turning into "ns:user": {...} and mapping the URI declarations to @xmlns keys. However, many modern APIs prefer clean JSON, so developers often configure their converters to strip namespaces entirely, dropping the prefix and turning simply into "user": {...}. You must choose the approach that best fits the requirements of the application consuming the JSON.

XML to JSON Converter

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