XML Minifier

Which whitespace is safe to drop

XML has no notion of “insignificant” whitespace in the parser itself: every space between tags is a text node that a program could read. In practice, though, the line breaks and indentation between elements that contain only other elements (element-only content, like <items> holding a list of <item>) are formatting, and every schema-driven consumer ignores them. That is what this minifier removes. The XML printer classifies each element before deciding:

• Element-only content: whitespace-only text between child elements is dropped.
• Mixed content, where text and elements sit side by side as in <p>Hello <b>world</b> and friends</p>, is copied exactly, so the spaces around <b> survive and the sentence still reads correctly.
• Leaf text such as <title> Release notes </title> keeps its leading and trailing spaces, because they are data.
• Elements marked xml:space="preserve", and everything inside them, are left untouched.
• CDATA sections are emitted verbatim, including any runs of spaces.

Inside tags, line breaks between attributes collapse to a single space, and single-quoted attribute values are rewritten with double quotes when that needs no escaping.

What else is removed, and what is kept

Comments are removed by default. Turn on Keep comments when minifying when they carry meaning, such as licence headers, generator notes or conditional markers a downstream tool looks for. The XML declaration, DOCTYPE, processing instructions and namespace declarations are always kept.

Entity references are written back as they appear. &co; stays &co; even when the internal DTD defines it; the built-in XML tokenizer never expands DTD entities, which also protects you from “billion laughs” style expansion attacks. The output means the same thing to a validating parser as the input did.

Two other options apply in minify mode. Empty elements set to Self-close <a/> shortens every <item></item> to <item/>, a few bytes each that add up in large exports. Collapse whitespace-only elements (on by default) empties elements that contain nothing but whitespace, again except where xml:space="preserve" applies or inside <text> and <xsl:text>, where a space is real output. The toolbar’s Sort keys sorts attributes, namespace declarations first, which helps when comparing two exports.

Savings and when to use it

The first example shrinks from 335 to 263 bytes, about 21%, and deeply indented SOAP envelopes or Android resource files gain more. Minified XML is useful for payloads embedded in JSON strings or database columns, SOAP request templates, and test fixtures you want on a single line. For files that people edit, keep the formatted version in source control and minify at build time.

Press Ctrl/Cmd+Shift+M to switch between minified and formatted output, and Ctrl/Cmd+Shift+C to copy the result. The document is processed entirely in your browser.

Validation comes first

A minifier that guesses on broken markup produces broken markup that is harder to read. Every input is parsed before anything is printed, so a mismatched closing tag, an unescaped &, an unquoted attribute or a second root element stops with an error pointing at the line and column, just as on the XML validator.

Examples

<?xml version="1.0" encoding="UTF-8"?>
<!-- exported 2026-09-14 -->
<orders>
  <order id="ord_8f2k1" status="paid">
    <customer>Aisha Tan</customer>
    <note><![CDATA[Leave at   the door & ring twice]]></note>
    <items>
      <item sku="KB-104" qty="1"/>
      <item sku="MS-220" qty="2"></item>
    </items>
  </order>
</orders>

<?xml version="1.0" encoding="UTF-8"?><orders><order id="ord_8f2k1" status="paid"><customer>Aisha Tan</customer><note><![CDATA[Leave at   the door & ring twice]]></note><items><item sku="KB-104" qty="1"/><item sku="MS-220" qty="2"></item></items></order></orders>

<?xml version="1.0"?>
<!-- exported 2026-09-14 -->
<orders>
  <order id="1">
    <items>
      <item sku="KB-104"></item>
    </items>
  </order>
</orders>

<?xml version="1.0"?><!-- exported 2026-09-14 --><orders><order id="1"><items><item sku="KB-104"/></items></order></orders>

<?xml version="1.0"?>
<feed>
  <title>  Release notes  </title>
  <entry id="1">
    <pre xml:space="preserve">  keep   me  </pre>
  </entry>
</feed>

<?xml version="1.0"?><feed><title>  Release notes  </title><entry id="1"><pre xml:space="preserve">  keep   me  </pre></entry></feed>

Common errors and how to fix them

Related tools

• XML formatter
• xml validator
• XML to JSON
• svg minifier
• html minifier
• json minifier