< Codevup />

Online XML Formatter and Validator

Input
Output
Formatted XML will appear here...
What is an online XML formatter and validator?
An online XML formatter takes raw, compressed, or poorly indented XML and reformats it with consistent indentation and line breaks, making it easy to read and debug. The built-in validator checks the structure against XML well-formedness rules and immediately reports any errors, such as unclosed tags, mismatched element names, or illegal characters in attribute values.
How do I prettify or beautify XML online?
Paste your XML into the left panel. The formatted output appears instantly in the right panel. You can choose between 2-space and 4-space indentation. The result is ready to copy with a single click. No button press required.
How does XML validation work?
The tool uses the browser native DOMParser with the application/xml MIME type. If the document is not well-formed, the parser returns a parsererror element describing what went wrong and where. The error message is displayed below the panels so you can fix the issue immediately.
What is the difference between well-formed and valid XML?
Well-formed XML follows the basic syntax rules: every opening tag has a closing tag, tags are properly nested, attribute values are quoted, and there is exactly one root element. Valid XML additionally conforms to a schema (DTD or XSD) that defines which elements and attributes are allowed. This tool checks well-formedness only, since schema validation requires a separate schema document.
What are the most common XML errors?
The most frequent XML errors are: unclosed tags (every <tag> needs a </tag> or self-closing <tag/>), improperly nested elements, unescaped special characters (use &amp;, &lt;, &gt;, &quot;, &apos;), missing quotes around attribute values, and multiple root elements.
Is my XML data safe and private?
Yes. All parsing and formatting happens entirely inside your browser using the native DOMParser API. Your XML is never uploaded to or stored on any server. This makes the tool safe to use with sensitive configuration files, API responses, or internal data.
Should I use 2-space or 4-space indentation for XML?
There is no universal standard. 2-space indentation is common in web and JavaScript ecosystems. 4-space indentation is preferred in Java and .NET projects where XML configuration files (like pom.xml, web.config, or AndroidManifest.xml) are common. Choose whatever matches your project or team style guide.
Can I format large XML files?
Yes. Because everything runs locally in your browser, there is no server-side file size limit. Very large XML documents may cause a brief processing delay depending on your device, but the tool will handle them without upload restrictions or timeouts.
What is XML?

XML (eXtensible Markup Language) is a text-based format for storing and transporting structured data. It was defined by the W3C in 1998 and is both human-readable and machine-readable. Unlike HTML, XML has no predefined tags: you define your own element names to match your data model.

An XML document is made up of nested elements delimited by opening and closing tags (e.g. <price>9.99</price>), attributes inside the opening tag (e.g. currency="USD"), and a single root element that wraps everything else. Every document must also be well-formed: tags must be properly closed and nested, and special characters must be escaped.

XML is widely used in configuration files (pom.xml, AndroidManifest.xml, web.config), data exchange formats (SOAP, RSS, Atom, SVG, XHTML), and enterprise systems such as SAP and Apache Kafka Connect. Even though JSON has largely replaced XML in REST APIs, XML remains dominant in legacy integrations, document formats (DOCX, XLSX, ODF), and industries like finance, healthcare (HL7), and publishing.