XML Formatter

About the XML Formatter

Paste XML — a SOAP or API response, an Android layout, an RSS feed, a sitemap, a Maven pom.xml or an SVG file — and get it neatly indented, or minified onto one line. The formatter only changes the whitespace between tags: comments, CDATA sections, processing instructions, the DOCTYPE and every attribute value are kept exactly as written, and text is never trimmed.

As you type, the document is checked against the well-formedness rules of XML 1.0. Problems are reported with the exact line and column and a plain explanation — a closing tag that does not match, an unescaped &, an attribute without quotes — and your browser's own XML parser double-checks the result.

Common uses

• Reading minified API, SOAP or payment-gateway responses while debugging.
• Tidying Android layouts, Maven and .NET project files, or SVG icons before committing them.
• Checking an RSS feed or a sitemap for syntax errors before publishing it.
• Minifying XML to make a payload or a config file smaller.

What well-formed XML means

A well-formed document follows the syntax rules of the XML 1.0 specification:

• There is exactly one root element that contains everything else.
• Every start tag has a matching end tag in the right order, or is self-closing like <br/>. Names are case-sensitive: <Item> is not closed by </item>.
• Attribute values are always in quotes, and an attribute appears only once per element.
• In text and attribute values, < must be written < and & must be written &. Only five entities are predefined: < > & ' "; others such as   must be declared in a DOCTYPE.
• The XML declaration <?xml version="1.0"?>, if present, must be the very first thing in the file.

What the formatter changes — and what it never touches

• Changes: line breaks and indentation between tags, and the spacing between attributes.
• Never changes: text content, attribute values and their quote style, comments, CDATA sections, processing instructions, the DOCTYPE and entity references.
• Keeps on one line, exactly as written: elements that mix text and tags, elements with single spaces between tags (such as <b>a</b> <i>b</i>), and anything inside xml:space="preserve".
• Whitespace-only content that contains a line break is treated as indentation and replaced.

Well-formed is not the same as valid

This tool checks that the document is well-formed. It does not validate it against a schema (DTD, XSD or RELAX NG) — for example it cannot tell you that <price> is required inside <product>. Namespace mistakes are reported as warnings, because most XML tools reject them: a prefix used without an xmlns: declaration, a name with more than one colon, the reserved xml and xmlns prefixes used wrongly, or one attribute written twice through two prefixes for the same namespace.

Limitations

• No schema validation (DTD, XSD, RELAX NG). External DTDs are not loaded, so entities defined only there cannot be checked.
• Whitespace-only text with a line break between tags is treated as formatting. Use xml:space="preserve" where such whitespace matters.
• Documents are processed on your device; very large files (tens of megabytes) can take a few seconds on older phones. Files over 1 MB are formatted without being loaded into the editor, and only the first 400 KB of a large result is shown — Copy and Download always include everything.
• Documents nested thousands of levels deep can be checked and minified but not indented, because the indentation alone would run to many megabytes.
• XML 1.1 documents are checked with the XML 1.0 character rules.

Privacy

Everything happens in your browser. What you enter or open here is not uploaded or stored by MySmartCoPilot.