Convert JSON to XML in C#

JSON and XML have different data models, so there is no single universal conversion. Libraries make choices about roots, arrays, attributes, text nodes, nulls, and invalid XML element names; document those choices in APIs.

Quick Start#

The following example uses the standard C# API or a widely used package for this task.

Using Newtonsoft.Json#

1// dotnet add package Newtonsoft.Json2using Newtonsoft.Json;3using System.Xml;45XmlDocument? doc = JsonConvert.DeserializeXmlNode(inputJson, "root");6string xml = doc?.OuterXml ?? "<root />";7Console.WriteLine(xml);

Common Operations#

This second pattern covers a common production operation or a safer way to handle real input.

Indented XML#

1using var stringWriter = new StringWriter();2using var xmlWriter = XmlWriter.Create(stringWriter, new XmlWriterSettings { Indent = true });3doc!.Save(xmlWriter);4xmlWriter.Flush();5string prettyXml = stringWriter.ToString();

Important Notes#

The JSON/XML mapping used by Newtonsoft.Json is a convention. Verify arrays, attributes, and text nodes against the documents your application needs to exchange.

Best Practices#

1. Treat external input as untrusted and handle parse/validation errors explicitly.
2. Keep encoding, units, formats, and library-specific mapping rules explicit at system boundaries.
3. Add test vectors that cover empty input, Unicode text, malformed input, and representative production data.

References#

• RFC 8259: JSON
• W3C XML
• .NET API Browser