XML Formatter & Validator
Check XML 1.0 namespace syntax and format compact element containers while retaining text, references, comments and CDATA.
About this xml formatter & validator
Check XML 1.0 namespace syntax and format compact element containers while retaining text, references, comments and CDATA Transforms and validates developer data structures locally, preventing confidential payload exposure during data wrangling.
Syntax parsing & data transformation logic
Checks XML 1.0 and Namespaces in XML 1.0 syntax, then adds two-space indentation to compact containers containing elements but no text or CDATA. Existing text, character references, attribute spelling, comments, processing instructions and CDATA are retained. Mixed content and xml:space="preserve" subtrees are kept together.
Worked conversion & output example
Scenario: Load the sample or paste an XML document.
Sample input:
Processing:
Illustrative output:
Syntax constraints & input size limits
Input: at most 1,000,000 UTF-16 code units. Output: at most 8,388,608. Nesting: at most 100 element levels. Only XML 1.0 without a DTD is supported; DOCTYPE declarations and unknown entities are rejected. This is a syntax check, not XSD or DTD validation, canonicalization, or byte-for-byte preservation. A leading BOM and whitespace outside the root may be replaced. Existing indentation inside elements is retained. Encoding declarations are retained as text; the tool does not encode a file. The visible workspace offers no file-upload or download control.
Data conversions and formatting in XML Formatter & Validator reflect standard structured syntax. Verify parsed outputs against your target runtime before deployment.
Local client execution boundary
Data parsing and transformations in XML Formatter & Validator execute in the local browser tab without remote data transmission.
Data format specifications & language standards
Data interchange formats and language grammar specifications:
XML Formatter & Validator verification · Audit standards
How to use it
- Enter, paste, or select your input data into the XML Formatter & Validator workspace controls.
- Choose Run locally.
- Check the nested elements and copy the complete result.
Frequently asked questions
What does XML Formatter do to a compact element with text and attributes?+
For `<root><item id="1">Ada</item></root>`, it writes root and item on indented lines while retaining the attribute and text: `<item id="1">Ada</item>`.
Does formatting validate an XSD or fetch external entities?+
No. The formatter checks XML grammar and formats lexical structure; it is not XSD validation, and it does not resolve an external entity as a network request.
Why are some XML nodes intentionally kept on one line?+
Text-only elements such as the recorded item example remain compact inside their opening and closing tags. The formatter adds structural indentation rather than rewriting text content.
What XML input boundary should I check before formatting?+
The page accepts nonempty, well-formed XML text within its size bound and valid XML characters. It preserves lexical spans where possible; a formatted document is not proof of schema or business-data validity.