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This draft contains only sections that have differences from the version that it modified.

W3C

XML Path Language (XPath) 4.0 WG Review Draft

W3C Editor's Draft 23 February 2026

This version:
https://qt4cg.org/specifications/xpath-40/
Most recent version of XPath:
https://qt4cg.org/specifications/xpath-40/
Most recent Recommendation of XPath:
https://www.w3.org/TR/2017/REC-xpath-31-20170321/
Editor:
Michael Kay, Saxonica <mike@saxonica.com>

Please check the errata for any errors or issues reported since publication.

See also translations.

This document is also available in these non-normative formats: XML.

Copyright © 2000 W3C® (MIT, ERCIM, Keio, Beihang). W3C liability, trademark and document use rules apply.

Abstract

XPath 4.0 is an expression language that allows the processing of values conforming to the data model defined in [XDM 4.0]. The name of the language derives from its most distinctive feature, the path expression, which provides a means of hierarchic addressing of the nodes in an XML tree. As well as modeling the tree structure of XML, the data model also includes atomic items, function items, maps, arrays, and sequences. This version of XPath supports JSON as well as XML, and adds many new functions in [Functions and Operators 4.0].

XPath 4.0 is a superset of XPath 3.1. A detailed list of changes made since XPath 3.1 can be found in I Change Log.

Status of this Document

This is a draft prepared by the QT4CG (officially registered in W3C as the XSLT Extensions Community Group). Comments are invited.

Dedication

The publications of this community group are dedicated to our co-chair, Michael Sperberg-McQueen (1954–2024).

Michael was central to the development of XML and many related technologies. He brought a polymathic breadth of knowledge and experience to everything he did. This, combined with his indefatigable curiosity and appetite for learning, made him an invaluable contributor to our project, along with many others. We have lost a brilliant thinker, a patient teacher, and a loyal friend.

B Context Components

The tables in this section describe the scope (range of applicability) of the various components in a module's static context and dynamic context.

B.1 Static Context Components

The following table describes the components of the static context. For each component, “global” indicates that the value of the component applies throughout an XPath expression, whereas “lexical” indicates that the value of the component applies only within the subexpression in which it is defined.

Static Context Components
ComponentScope
XPath 1.0 Compatibility Modeglobal
Statically known namespacesglobal
Default element/type namespaceglobal
Default function namespaceglobal
In-scope schema typesglobal
In-scope element declarationsglobal
In-scope attribute declarationsglobal
In-scope variableslexical; for-expressions, let-expressions, and quantified expressions can bind new variables
Context value static typelexical
Statically known function signaturesglobal
Statically known collationsglobal
Default collationglobal
Base URIglobal
Statically known documentsglobal
Statically known collectionsglobal
Statically known default collection typeglobal