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XML Formatter & XML to JSON

Free online XML formatter, minifier, and XML to JSON converter. Beautify messy XML, minify for production, or convert between XML and JSON — all in your browser.

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XML Formatter & XML to JSON is a free, browser-based tool from UseToolSuite's Format & Convert Tools collection. All processing happens locally on your device — your data is never uploaded to any server. Use the tool below, then scroll down for detailed documentation, frequently asked questions, and related resources.

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What is XML Formatter?

XML Formatter is a free online tool that beautifies, minifies, and converts XML data. Paste messy or minified XML and instantly format it with proper indentation, convert XML to JSON for easier data manipulation, or convert JSON back to XML. All processing happens entirely in your browser using the native DOMParser API — your data never leaves your device.

When to use it?

Use XML Formatter when working with XML-based APIs (SOAP, RSS, Atom), Android manifest files, Maven/Gradle configuration files, or any XML data that needs to be readable. The XML to JSON converter is useful when you need to transform XML API responses into JSON for JavaScript applications, or when migrating from XML-based configs to JSON format.

Common use cases

Developers use XML Formatter to debug SOAP API responses, inspect RSS and Atom feeds, format Android layout XML files, clean up Maven POM files, convert XML configuration to JSON for modern frameworks, and prepare XML data for documentation or code reviews. DevOps engineers use it to inspect and validate CI/CD pipeline configurations that use XML format.

Three jobs in one tool

XML work splits into formatting and converting, and this tool covers both directions of each:

TaskWhat it doesWhen
BeautifyIndents and line-breaks messy XMLReading / debugging
MinifyStrips whitespace for transportProduction payloads
XML → JSONConverts to a JS-friendly objectConsuming XML in JS
JSON → XMLConverts back to markupProducing XML output

How attributes survive the conversion

XML’s attribute/element distinction has no JSON equivalent, so the converter uses a convention: attributes become keys prefixed with @, and an element’s text content (when it also has attributes) lands under a #text key. So <book id="bk1">Title</book> becomes { "book": { "@id": "bk1", "#text": "Title" } }. This preserves every piece of information for a lossless round-trip — and tells you exactly what to look for when navigating the resulting JSON.

CDATA: escaping without the escaping

When an element’s text is full of characters that would otherwise need escaping — an HTML snippet, a code sample, a string with many <, >, and & — wrapping it in a CDATA section (<![CDATA[ ... ]]>) tells the parser to treat the contents as literal text, not markup. It’s far more readable than escaping every character into entities. The formatter preserves CDATA sections; reach for them whenever you’re embedding markup-like content inside XML.

Fixing “not well-formed” errors

The DOMParser reports a specific error when XML breaks the rules, and the cause is almost always one of a short list: an unclosed tag, an unescaped & (use &amp; — common in URLs), more than one root element, or a tag name starting with a digit. Escape the five reserved characters (&, <, >, ", '), ensure a single root, and most parse failures resolve. All parsing happens locally via the browser’s native APIs, so your XML never leaves your device.

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Key Concepts

Essential terms and definitions related to XML Formatter & XML to JSON.

XML (Extensible Markup Language)

A markup language for encoding structured data in a human-readable and machine-readable text format. Unlike HTML, XML tags are not predefined — you define your own elements and attributes. XML is widely used for configuration files (Maven, Android), data interchange (SOAP APIs, RSS feeds), and document formats (SVG, XHTML, Office Open XML).

DOMParser

A browser-native API that parses XML or HTML strings into a DOM Document object. For XML, it performs full syntax validation and returns a parsererror element if the input is not well-formed. This tool uses DOMParser for XML parsing, ensuring standards-compliant validation without any external library.

CDATA Section

A section in XML (wrapped in <![CDATA[...]]>) where text content is treated as literal character data, not parsed as XML markup. CDATA sections are used to include content that would otherwise require extensive entity escaping, such as HTML snippets, JavaScript code, or text containing many special characters.

Frequently Asked Questions

Does this tool validate XML syntax?

Yes. The formatter uses the browser's native DOMParser which validates XML against the XML 1.0 specification. If your XML contains syntax errors like unclosed tags, missing attributes, or invalid characters, the tool will display the specific error message from the parser.

How does XML to JSON conversion handle attributes?

XML attributes are converted to JSON properties prefixed with @ (e.g., @id, @class). Text content of elements with attributes is stored under the #text key. This convention preserves all information from the original XML and allows lossless round-trip conversion.

Can I convert JSON back to XML?

Yes. The tool supports bidirectional conversion. Click "JSON → XML" to convert a JSON object back to XML format. The converter recognizes @ prefixed keys as attributes and #text as element text content.

Does it handle XML namespaces?

The formatter preserves standard XML namespaces and their prefixed elements. Namespace declarations (xmlns) are maintained in the formatted output. The XML to JSON converter includes namespace prefixes in the JSON keys.

Is my XML data sent to any server?

No. All formatting, minification, and conversion happens entirely in your browser using the native DOMParser and XMLSerializer APIs. Your data never leaves your device.

What's the difference between well-formed and valid XML?

Well-formed means the XML follows the basic syntax rules: one root element, every tag closed, proper nesting, attributes quoted, and special characters escaped. The browser's DOMParser (which this tool uses) checks well-formedness and rejects anything that breaks those rules. Valid is a stronger claim — it means the XML also conforms to a specific schema (a DTD, XSD, or RelaxNG) that defines which elements, attributes, and structures are allowed for that document type. All valid XML is well-formed, but well-formed XML can still be invalid against a schema. This tool verifies well-formedness; schema validation requires the schema and a validating parser.

Why does my XML-to-JSON output sometimes use an array and sometimes a single object?

Because XML doesn't mark whether an element repeats — it just appears once or several times. When the converter sees one <item>, it produces a single object; when it sees multiple <item> siblings, it groups them into an array. That means the SAME schema can produce different JSON shapes depending on how many items a particular document happens to contain, which can break code that always expects an array. The defensive pattern: in your consuming code, normalize — if the field isn't an array, wrap it in one — so a one-element and a many-element response are handled identically.

Troubleshooting & Technical Tips

Common errors developers encounter and how to resolve them.

DOMParser error: XML Parsing Error — not well-formed

This error means your XML has syntax issues. Common causes: unclosed tags (<tag> without </tag>), unescaped special characters (use &amp; for &, &lt; for <, &gt; for >), missing root element (XML must have exactly one root), or invalid tag names (cannot start with numbers). Fix these issues in your source XML and try again.

XML to JSON produces unexpected structure with repeated elements

When an XML element has multiple children with the same tag name, the converter groups them into a JSON array. For example, multiple <item> elements become "item": [...]. If you have a single <item>, it will be a direct value; with multiple items, it becomes an array. This is standard XML-to-JSON conversion behavior.

Special characters like & or < cause parsing failure

XML requires escaping of five special characters: & → &amp;, < → &lt;, > → &gt;, " → &quot;, ' → &apos;. If your XML contains unescaped ampersands in URLs or text content, they must be escaped. Alternatively, wrap content containing special characters in a CDATA section: <![CDATA[content with & and < here]]>.

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