XML Formatter and Validator

This tool gives a quick browser-based check for well-formed XML and formats a small document so nested elements and attributes are easier to inspect.

Designed for: Developers, QA testers, and technical writers inspecting small XML fixtures or configuration files.

How to use this tool

Paste XML and choose the indentation width. The browser parser reports a parser error when it cannot read the document; valid XML is serialized and formatted for review.

How the result is produced

The tool uses the browser DOMParser with the application/xml MIME type and XMLSerializer for output. Formatting is a readability pass, not a schema validation step.

Test examples

<items><item id="1">One</item></items> is well-formed and can be displayed with nested indentation. An unclosed element such as <item>One produces a parser error.

Limitations

Well-formed XML is not the same as valid XML for a particular XSD, DTD, API, or application. Namespace behavior, external entities, very large documents, and dialect-specific rules need a standards-aware workflow.

Privacy and processing

The XML is parsed and formatted in the browser. It is not uploaded by this tool.

Related guide

Well-formed XML versus schema-valid XML

Related tools in this category

• JSON Formatter and ValidatorPaste a JSON object or array, then format it or validate its syntax.
• Base64 Encoder and DecoderChoose encode or decode. The browser performs the conversion locally.
• Unix Timestamp ConverterConvert a date-time to Unix seconds or convert seconds back to an ISO-style date.

Documentation

• https://developer.mozilla.org/en-US/docs/Web/API/DOMParser
• https://www.w3.org/TR/xml/

This page describes the implementation shipped with the NOFYI Tool Factory. Review the interface output before using it in a production workflow.