XML Formatter Validator Tool - Online XML Beautifier with XPath Tester and Tree Viewer

First Published: 2026-04-01
Last Updated: 2026-04-01

Free online XML formatter, validator, beautifier, minifier with XPath expression tester, XML to JSON converter, and namespace-aware tree viewer with syntax highlighting. All processing is performed entirely in your browser - your XML data never leaves your device.

⚠️ IMPORTANT DISCLAIMER:

This tool is provided "AS IS" without any warranties of any kind.
The author accepts no responsibility for data loss or any issues arising from use of this tool.
Do not paste sensitive or confidential data without understanding that all processing is local.
Always keep backups of your original data.
By using this tool, you accept full responsibility for any outcomes.

This tool uses client-side JavaScript for all processing. No data is transmitted to servers, no files are uploaded online, all processing happens locally in your browser. Once loaded, this tool continues to work even without an internet connection. For more details, please refer to our Web Tools Disclaimer.

XML Input:

Indentation:

Attr prefix: Text key:

📁 Drop an XML file here, or click to select a file (max 5MB)

How to Use This XML Formatter Tool

Enter XML: Paste your XML data into the input area, or drag and drop an XML file
Choose Action: Click "Format" to beautify, "Minify" to compress, "Validate" to check syntax, or "To JSON" to convert
Select Indentation: Choose between 2 spaces, 4 spaces, or tab indentation
View Results: Switch between Formatted text (syntax-highlighted), interactive Tree View, and XPath Tester
Test XPath: Switch to the XPath Tester tab, enter an expression, and click Evaluate to find matching nodes
Copy Result: Use "Copy" button to copy the formatted, minified, or JSON output

Pro Tip: Press Ctrl+Enter (or Cmd+Enter on Mac) in the input area to quickly format your XML.

XPath Quick Reference

/root/child — Select child elements under root
//element — Select all matching elements anywhere in the document
//element[@attr] — Select elements that have a specific attribute
//element[@attr='value'] — Select elements with a specific attribute value
//element/text() — Select text content of elements
//element[position()=1] or //element[1] — Select the first matching element
//parent/* — Select all child elements of parent
//element[contains(@attr,'partial')] — Partial attribute match
count(//element) — Count matching elements (use with number result type)

Namespace Note: When using XPath with namespaced documents, use the declared prefixes in your queries (e.g., //dc:title). Elements in a default namespace (no prefix) cannot be queried directly with XPath 1.0 without a prefix mapping.

XML to JSON Conversion Rules

Attributes: Prefixed with the selected character (default: @), e.g., @id
Text content: Stored under the selected key (default: #text) when mixed with attributes or child elements
Leaf elements: Text-only elements without attributes are converted directly to string values
Repeated elements: Sibling elements with the same tag name are automatically grouped into JSON arrays
Namespace declarations: xmlns attributes are excluded from the JSON output

About XML (Extensible Markup Language)

XML is a markup language for encoding documents in a format that is both human-readable and machine-readable. It is widely used in web services (SOAP), configuration files (Maven POM, Spring, Android layouts), data interchange, and document formats (SVG, XHTML).

Well-formedness: All XML documents must have a single root element, properly nested tags, and closed elements
Attributes: Must be quoted with double or single quotes
Namespaces: Allow elements from different vocabularies to coexist using URI-based prefixes
CDATA: <![CDATA[...]]> sections allow unescaped text content
Processing Instructions: <?target data?> provide instructions to applications

Common XML Errors

Unclosed Tags: Every opening tag must have a corresponding closing tag or be self-closing
Unescaped Characters: &, <, > must be escaped as &, <, > in text and attributes
Mismatched Tags: Opening and closing tag names must match exactly (case-sensitive)
Missing Root Element: XML documents must have exactly one root element
Unquoted Attributes: Attribute values must always be enclosed in quotes
Invalid Characters: XML 1.0 does not allow certain control characters

Features:

✨ Format / Beautify: Pretty-print XML with configurable indentation (2 spaces, 4 spaces, or tabs) and full syntax highlighting
🗜️ Minify / Compress: Remove all whitespace to produce compact XML output
✅ Validate: Check XML well-formedness with detailed error location (line and column number)
🔄 XML to JSON: Convert XML to JSON with configurable attribute prefix (@, _, $) and text key (#text, _text, $text)
🔍 XPath Tester: Evaluate XPath expressions against your XML with namespace support and serialized node results
🌳 Tree View: Interactive collapsible tree with namespace-aware coloring, Expand All / Collapse All controls
🎨 Syntax Highlighting: Color-coded tags, attributes, namespaces, comments, CDATA, and processing instructions
📁 File Support: Drag and drop or select XML files up to 5MB
📊 Statistics: View XML size, element count, attribute count, nesting depth, and namespace count
📋 Easy Copy: One-click copy of formatted, minified, or JSON output
📱 Mobile Friendly: Responsive design works on all devices
🔒 Privacy First: All processing happens locally in your browser - no data sent to servers
⌨️ Keyboard Shortcut: Ctrl+Enter (Cmd+Enter) to format instantly

Common Use Cases:

SOAP / Web Services: Format and validate SOAP XML requests and responses
Configuration Files: Validate Maven POM, Spring XML, Android layouts, and other config files
Data Interchange: Convert XML data feeds to JSON for modern API consumption
XPath Development: Test and debug XPath expressions before using them in code or XSLT transformations
SVG Editing: Format and inspect SVG (Scalable Vector Graphics) files
Debugging: Find syntax errors in XML payloads with precise error location
Data Transfer: Minify XML to reduce payload size for network transmission

References:
Tech Blog with curated related content
Web Tools Collection

Written by Hidekazu Konishi