xslt-lab/site/content/xslt/functions/xpath-upper-case.md

title, description, date, version, versionLabel, category, syntax, tags

title	description	date	version	versionLabel	category	syntax	tags
upper-case()	Converts every character of a string to its Unicode uppercase equivalent using locale-independent Unicode case mapping.	2026-04-18T00:00:00Z	2.0	XSLT 2.0	string function	upper-case(string)	xslt reference xslt2 xpath

Description

upper-case() returns a copy of the input string with every character converted to uppercase according to Unicode case mappings. The conversion is locale-independent and uses the Unicode default case folding rules — it does not consider language-specific rules (e.g., Turkish dotless-i). For language-sensitive uppercasing, a collation-aware approach or custom extension function is needed.

If the argument is an empty sequence, the function returns the empty string "".

Parameters

Parameter	Type	Required	Description
string	xs:string?	Yes	The string to convert.

Return value

xs:string — the input string with all characters mapped to uppercase.

Examples

Basic uppercase conversion

Input XML:

<?xml version="1.0" encoding="UTF-8"?>
<messages>
  <msg>Hello, World!</msg>
  <msg>xslt is powerful</msg>
  <msg>Ärger mit Ü</msg>
</messages>

Stylesheet:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:output method="xml" indent="yes"/>

  <xsl:template match="/messages">
    <upper>
      <xsl:for-each select="msg">
        <msg><xsl:value-of select="upper-case(.)"/></msg>
      </xsl:for-each>
    </upper>
  </xsl:template>
</xsl:stylesheet>

Output:

<upper>
  <msg>HELLO, WORLD!</msg>
  <msg>XSLT IS POWERFUL</msg>
  <msg>ÄRGER MIT Ü</msg>
</upper>

Case-insensitive comparison

Stylesheet:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:output method="xml" indent="yes"/>

  <xsl:template match="/catalog">
    <!-- Select items regardless of how 'active' is cased in the data -->
    <active-items>
      <xsl:for-each select="item[upper-case(@status) = 'ACTIVE']">
        <item><xsl:value-of select="name"/></item>
      </xsl:for-each>
    </active-items>
  </xsl:template>
</xsl:stylesheet>

Notes

• upper-case() is not the same as the i flag on matches(). The function changes the string; the flag changes how matching works.
• For true locale-aware uppercasing (e.g., Turkish i → İ), use an extension function or a collation-aware approach.
• Numeric, punctuation, and whitespace characters are returned unchanged.
• Combining upper-case() with normalize-unicode() can help with Unicode normalization before comparison.

See also

• lower-case()
• normalize-unicode()
• normalize-space()