XML Validator, Formatter and Linter

Syntax errors with line and column. Pretty-print with 4-space indent, or minify. XML Schema (XSD 1.0). Lint duplicate attributes and external DTDs. XML stays in your browser — nothing is uploaded.

Validate XML — line and column

Paste or type XML and get well-formedness errors with a line and column. Open a finding to jump to that spot in the editor.

Format and minify

Pretty-print with 4-space indent, or minify to a compact document. Formatting runs only when the document is well-formed XML.

XML Schema (XSD 1.0)

Paste an XSD to check the document. Schema checks use XML Schema 1.0 in the browser. Remote schemaLocation values are not fetched.

Lint what a silent parser hides

Some parsers keep the last value for a duplicate attribute and skip external DTDs. This linter reports those problems.

Your XML never leaves the browser

Validation, formatting, and schema checks run on your device. Nothing is uploaded.

Well-formedness

A document must have matching tags, quoted attributes, and one root element. Errors include line and column.

Duplicate attributes

XML does not allow the same attribute twice on one element. The linter reports both occurrences.

DTD / external entities

External DTD and entity references are not fetched. Use the Schema panel with a local XSD.

XSD 1.0

Schema checks use XML Schema 1.0 in the browser. Remote imports are not loaded.

Upload

XML stays in the browser. Nothing is uploaded.