XML Well-Formedness checker
Check whether XML is well formed without contacting an external service.
How to use the XML Well-Formedness checker
What does the XML Well-Formedness checker do?
Check whether XML is well formed without contacting an external service; It applies this page-specific rule: check whether XML is well formed without contacting an external service.
Which inputs does this tool use?
To check whether xml is well formed without contacting an external service, enter Input, Result; keep every value in the same example; select Check input when the values are ready; Start with a familiar case covered by this rule - The document is parsed to confirm one root element, matched tags, quoted attributes, and valid XML nesting - so the expected result can confirm the settings.
How should the tool result be read?
For a result intended to check whether xml is well formed without contacting an external service, the document is parsed to confirm one root element, matched tags, quoted attributes, and valid XML nesting; read result together with the original input rather than as an isolated answer, and confirm that its units or structure match the intended use.
Is well-formed the same as schema-valid?
When the goal is to check whether xml is well formed without contacting an external service, no.
Can XML contain more than one root element?
When using the page to check whether xml is well formed without contacting an external service, no.
Limits and accuracy
When using this tool to check whether xml is well formed without contacting an external service, well-formed XML can still violate an application schema or contain semantically incorrect values; a passing result confirms the rules tested on this page, but it does not prove that an address, identifier, account, or remote resource exists; keep input until the output has been checked in its intended destination. For a repeatable check when you need to check whether xml is well formed without contacting an external service, record Input alongside the final output and selected options.
What XML Well-Formedness checker does
Check whether XML is well formed without contacting an external service.
Enter the value or list you want to check in the labeled controls. The XML Well-Formedness checker result stays separate so you can review it before copying, downloading, or using it elsewhere.
Your work is processed in this browser tab. Keep the original whenever a conversion changes formatting, dimensions, or precision.
Frequently asked questions
Does this validate against an XSD?
This implementation parse XML with the browser XML parser and detect mismatched tags, invalid attributes, malformed entities, and namespace syntax errors. The output is well-formed status, parser diagnostics, source location, and an element-tree summary.
Are external entities loaded?
The tool handles only the format and rules described on this page. It focuses on XML's tag, entity, and namespace syntax rather than HTML recovery behavior. It does not contact a remote validation or lookup service.
Can it identify mismatched closing tags?
Input is processed by JavaScript in the current browser tab. Nothing entered in the tool is sent to Plain Tools; keep the original when the transformation is lossy.