What is XML formatting (pretty printing)?

Pretty printing adds consistent indentation and line breaks to XML that may have been minified or machine-generated as a single long line. Formatted XML is much easier to read and debug because the element hierarchy is visually clear. The structure and data are identical - only whitespace is added.

What is XML minification and when should I use it?

Minification removes all unnecessary whitespace, line breaks, and indentation to produce the most compact XML possible. Minified XML is smaller (saving bandwidth and storage) and faster to parse. Use it when preparing XML for production APIs, configuration files, or data transfers where human readability is not needed.

Does formatting validate my XML?

Yes. The formatter uses the browser's native DOMParser with "text/xml" mode, which performs well-formedness validation. If your XML has errors (unclosed tags, mismatched elements, illegal characters, missing root element), the tool will report a parse error with details about what went wrong.

What are the rules for well-formed XML?

Well-formed XML must: have exactly one root element, all elements must be properly closed or self-closed, attribute values must be quoted, tags are case-sensitive and opening/closing tags must match, special characters ( , &, ", ') must be escaped as entities (< > & " '), and the optional XML declaration must be at the very top.

What is the difference between 2-space and 4-space indentation?

2-space indentation produces more compact output with less horizontal scrolling, preferred by many style guides and used widely in JavaScript and web ecosystems. 4-space indentation is more readable at a glance and is the traditional choice in Java, Python, and enterprise XML schemas. Choose based on your team's conventions or the target system's style requirements.

Is my XML data kept private?

Yes. Formatting and validation are performed entirely in your browser using the native DOMParser API. No XML is ever sent to any server. This makes the tool safe for use with internal configuration files, API responses containing sensitive data, and proprietary document formats.

XML Formatter & Beautifier

Format and beautify XML online. Free XML formatter - pretty print, validate structure, and minify XML. Client-side only, no data leaves browser.

🔒 Your text stays in your browser - nothing is sent to our servers

Indent:

XML Input

Formatted XML

How to Use

Three steps to get started

Choose mode

Select "Format / Beautify" to pretty print your XML, or "Minify" to produce compact output.

Paste your XML

Paste any XML into the input area. If the XML is invalid, an error will appear describing the parse problem.

Copy the result

Copy the formatted or minified output for use in your editor, API, or configuration file.

About This Tool

XML: still everywhere in modern development

XML (Extensible Markup Language) is a W3C standard, first published in 1998, for encoding structured documents and data in a format that is both machine-parseable and human-readable. An XML formatterre-indents that markup so the nesting of elements is visible at a glance - adding only whitespace, never changing a tag, attribute, or value.

Despite the rise of JSON, XML remains ubiquitous. It powers SOAP web services, SVG graphics, Android layouts in res/layout, Maven pom.xmland Ant build files, the Office Open XML formats behind DOCX and XLSX, RSS and Atom feeds, sitemap.xml files that search engines crawl, EPUB books, and the ONIX, FpML, and HL7 CDA formats that publishing, finance, and healthcare run on.

When to format vs. minify

Format/Beautify - debugging a SOAP response, reading a config file, reviewing a diff, or writing documentation
Minify - trimming payload size on the wire, shrinking inline SVG in a build pipeline, or storing a document in a size-constrained column

One caution on minifying: whitespace is not always insignificant in XML. Inside mixed content - an element containing both text and child elements, as in XHTML - the spaces between them are real data, and collapsing them can change the rendered result. The xml:space="preserve" attribute exists precisely to mark regions where this must not happen.

Why does my XML fail to parse?

The formatter validates well-formedness through the browser's DOMParser, and a handful of mistakes account for most failures. A bare ampersand in a URL is the classic one - ?a=1&b=2 must be written?a=1&b=2 or wrapped in a CDATA section. Others: more than one root element, an unbound namespace prefix such as<soap:Body> with no matching xmlns:soapdeclaration, mismatched case (<Item>...</item> is an error because XML tags are case-sensitive), unquoted attribute values, and stray content before the <?xml version="1.0"?> declaration, which must be the very first thing in the file with no leading whitespace or BOM.

XML vs. JSON

XML is more verbose than JSON but offers capabilities JSON lacks: comments, namespaces to prevent element-name collisions when merging vocabularies, a real distinction between attributes and element content, processing instructions, document type declarations, and schema validation through XSD, DTD, or RELAX NG. It also has a mature transformation and query stack - XSLT for rewriting documents, XPath for addressing nodes, XQuery for database-style retrieval - with no direct JSON equivalent of comparable maturity. JSON wins on payload size and on mapping cleanly to native objects in JavaScript and Python, which is why new REST APIs default to it while document-centric and contract-heavy systems stay on XML.

Well-formedness is only half the story. A document can parse perfectly and still be invalid against its schema - DOMParser checks syntax, not whether<price> belongs inside <address>. For that you need an XSD validator.

All formatting and validation happens in your browser using the native DOMParser API. No XML data is ever sent to a server, which matters when the document is a signed SOAP envelope or a config file containing credentials.

FAQ

Frequently Asked Questions

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