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Developer ToolsUpdated 2025-04-11

XML Formatter and Validator: Clean Up Messy XML in One Click

Paste minified or messy XML and get perfectly indented, validated output. Catches syntax errors like unclosed tags and mismatched attributes before they cause problems.

Introduction

XML is everywhere: SOAP APIs, RSS feeds, Android layouts, Spring configs, SVG files, GPX tracks, Excel internals. When you receive a single-line block of minified XML from an API response, it is practically unreadable. Our XML Formatter takes that wall of angle brackets, validates its structure, and outputs beautifully indented XML that a human can actually read. It catches syntax errors like missing closing tags, unescaped characters, and mismatched nesting before they blow up your parser.

Step-by-Step Guide

1

Paste your XML

Copy your raw XML and paste it into the input panel. It does not matter if it is minified, partially formatted, or a complete mess. The formatter handles all of it.

2

Click Format

Hit the Format button. The tool parses the XML, validates the structure, and outputs properly indented XML with consistent spacing. Any syntax errors are displayed with the line number and description.

3

Copy the clean output

The formatted XML appears in the output panel with proper indentation. Click Copy to grab it, or download it as an .xml file.

Pro Tips & Best Practices

Pro Tip

If the formatter throws an error, check for ampersands (&) that are not escaped as & in text content. This is the most common XML validity issue.

Pro Tip

Use this tool to inspect API responses during development. Paste the raw response from your HTTP client and the formatted output makes the data structure obvious.

Pro Tip

For configuration files, consistent formatting is not just about readability. It also makes version control diffs cleaner since Git compares line by line.

Common Mistakes to Avoid

Common Mistake to AvoidConfusing XML with HTML. HTML is lenient about unclosed tags and attribute quoting. XML is strict. Every opening tag needs a closing tag, and every attribute value must be quoted.
Common Mistake to AvoidIgnoring namespace declarations. If your XML uses namespaces (xmlns attributes), removing them will break parsers that depend on qualified element names.
Common Mistake to AvoidExpecting the formatter to fix invalid data. The tool can indent and validate structure, but it cannot fix semantic errors like putting the wrong value in an element.

Frequently Asked Questions

Does this validate XML against a schema (XSD)?

No. The tool validates well-formedness (correct syntax, matched tags, proper nesting) but does not validate against external schemas. For XSD validation, you need a dedicated XML schema validator.

Can I choose the indentation style?

The default indentation is 2 spaces, which is the most common convention for XML. The formatted output is clean and consistent regardless of how the input was formatted.

Does it handle CDATA sections and processing instructions?

Yes. CDATA sections (for embedding raw text) and processing instructions (like <?xml version="1.0"?>) are preserved exactly as they appear. The formatter does not alter content inside CDATA blocks.

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