Free XML Checker
XML Checker is a browser-based tool that helps you validate, inspect, and analyze XML without installing anything. We built this workspace so you can catch syntax errors, inspect tag distribution, verify encoding declarations, review namespace usage, and measure nesting depth in one place. You can paste XML directly or upload a file and get visual results instantly.
XML Checker Overview
Use one workspace to validate XML well-formedness, inspect tag frequency, verify declaration fields, review namespaces, and analyze depth with visual dashboards.
XML Checker
Detect unclosed tags, mismatched elements, and unescaped special characters with severity cards, line numbers, and summary metrics.
Tag Inspector
See how often each tag appears, whether tags use attributes, and which elements dominate your XML structure.
Encoding Check
Read version, encoding, and standalone values from your XML declaration and catch missing or non-standard metadata.
Namespace Check
Audit namespace declarations, count prefix usage, and flag prefixes that are undeclared or declared but unused.
Depth Analyzer
Measure maximum and average nesting depth, review level-by-level counts, and inspect the deepest element path.
Online XML Checker for Error Detection
XML issues are easy to miss in large documents. A single malformed tag or unescaped character can break feeds, APIs, imports, and integrations. We designed this online XML Checker so you can identify problems quickly with a visual report that highlights severity, line context, and structural metrics.
Well-Formedness Validation
The checker verifies core XML syntax rules including proper tag closure, correct nesting order, and escaped entities where required. You get a status banner plus issue cards that clearly show what is wrong and where to fix it. This helps you validate confidently before deployment or data exchange.
Upload XML Files Directly
You can drag and drop files or use the upload button for fast analysis. Supported formats include .xml, .xsl, .xslt, .svg, .xhtml, .rss, and .atom. This makes it easy to test real production files, exported feeds, and generated XML documents without conversion steps.
Inspect Tags, Encoding, and Namespaces
Validation is only one part of XML quality. We also help you understand document composition and metadata so you can maintain cleaner, more predictable XML over time.
Tag Inspector
Tag Inspector shows you frequency distribution by tag name, total element volume, and whether tags carry attributes. This is useful when auditing generated XML from CMS exports, feeds, and API payloads where structure can drift over time.
Encoding and Namespace Checks
Encoding Check reviews declaration fields and flags missing values before they cause cross-system parsing issues. Namespace Check lists every declared prefix, measures usage counts, and identifies undeclared or unused prefixes so your document remains explicit and consistent.
Depth Analyzer
Depth Analyzer reveals how deeply nested your XML has become. You get maximum depth, average depth, a visual gauge, the deepest traversal path, and a level breakdown. These insights help you spot over-nested designs and simplify complex XML structures.
Your Data Stays on Your Device
We process everything directly in your browser using DOMParser and JavaScript. Your XML is not sent to our servers, and there is no signup requirement. You can safely validate internal configs, XML feeds, and integration payloads while keeping your data local.
Related XML and Data Tools
If you work with XML regularly, these free tools complement the checker:
- XML Optimizer -- optimize XML by stripping comments and whitespace
- XML Formatter -- format, minify, validate, and convert XML
- XML Beautifier -- beautify and indent XML with syntax highlighting
- XML Pretty Print -- pretty print XML with configurable indentation
- XML Minifier -- minify XML with comment and whitespace removal
- XPath Tester -- test XPath expressions against XML documents
- JSON Formatter -- format, minify, validate, and transform JSON
- HTML Minify -- minify, expand, validate, and transform HTML code