Free XML Lint Tool
XML Lint is a browser-based linter that scans your XML documents for syntax errors, code quality warnings, and structural issues. We built five XML analysis utilities into one workspace so you can lint, auto-fix, check structure, compare documents, and review statistics without installing software or creating an account. Paste your XML or upload a file and get instant results. Your data stays on your device at all times.
XML Lint Overview
Lint XML for errors, warnings, and suggestions in one workspace. Includes auto-fix, structure validation, line-by-line diff, and full document statistics.
XML Lint
Detect parse errors, unescaped characters, TODO comments, mixed indentation, empty elements, and duplicate attributes with color-coded issue cards.
Syntax Fix
Auto-repair common XML problems including unescaped ampersands, missing declarations, and unclosed tags with pretty-printed output.
Structure Check
Analyze element hierarchy, parent-child relationships, and flag consistency issues where sibling elements have different structures.
XML Diff
Compare two XML documents side by side with a unified diff report showing added, removed, changed, and unchanged lines.
XML Stats
Review comprehensive document statistics including element counts, tag frequency tables, depth analysis, and attribute breakdowns.
How the Linter Reports Issues
When you paste or upload XML, the linter scans every line and runs the document through the browser DOMParser. Parse errors surface immediately with line numbers and descriptions. Beyond syntax, we check for unescaped ampersands, trailing whitespace, mixed tabs and spaces, TODO and FIXME comments, empty elements, and duplicate attributes. Each issue appears as a color-coded card. Errors show in red, warnings in amber, and informational hints in blue. A live counter in the toolbar gives you an at-a-glance summary so you know exactly how many issues remain.
Upload XML Files Directly
You can upload files in .xml, .xsl, .xslt, .svg, .xhtml, .rss, and .atom formats using the Upload File button. The file is read using the browser File API, so nothing is transmitted. This makes it easy to lint production configs, RSS feeds, SOAP definitions, and exported data files without copy-pasting.
Online XML Lint for Structure and Quality
Catching parse errors is only the first step. Real XML quality means consistent structure, clean encoding, and no leftover development artifacts. We designed these tools to go beyond basic validation and give you actionable insights about your documents.
Syntax Fix for Quick Repairs
When the linter finds problems, you can switch to Syntax Fix to attempt automatic repair. The tool escapes unescaped ampersands, adds a missing XML declaration, and closes unclosed tags. If the resulting XML parses correctly, it is pretty-printed with proper indentation. This saves time when you are cleaning up generated XML, CMS exports, or hand-edited config files with minor mistakes.
Structure Check for Consistency
Structure Check maps every parent-child element relationship in your document and flags inconsistencies. If you have a list of product elements where some have four children and others have three, the checker highlights the discrepancy. This is useful when processing XML from multiple sources or verifying that code generators produce uniform output.
XML Diff for Version Comparison
XML Diff compares two documents line by line and produces a unified report. Changed lines are marked with + and - prefixes, and a summary shows exact counts of changes, additions, removals, and matches. Use this to verify configuration changes, compare API responses, or review XML exports across environments.
XML Stats for Document Intelligence
XML Stats walks your entire document tree and generates a detailed report. You get line count, character count, file size, total elements, unique tag names, attribute totals, depth analysis with a visual gauge, level-by-level breakdowns, tag frequency tables, and attribute frequency tables. These insights help you understand document complexity, plan refactoring, and set size budgets.
Your Data Stays on Your Device
We process everything in your browser using the built-in DOMParser API and JavaScript. Your XML never touches our servers. You can safely lint production configs with credentials, SOAP definitions with internal endpoints, and data feeds with customer information. No server communication, no cookies, no signup.
Related XML and Developer Tools
If you work with XML regularly, these free tools complement what you can do here:
- XML Checker -- validate XML well-formedness with tag inspection and depth analysis
- XML Formatter -- format, minify, validate, and convert XML
- XML Optimizer -- optimize XML by stripping comments and whitespace
- 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 data