XML Validator checks XML well-formedness and reports parser errors; it does not apply DTD, XSD, or application business rules. Essential for developers catching structural XML issues before integration, validating API responses, and debugging configuration file syntax.
XML tools
XML Input
Drag & drop supported
Validation result
Paste XML on the left to validate.
XML Validator checks XML well-formedness and reports parser errors; it does not apply DTD, XSD, or application business rules.
Reviewed: 2026-09-18
Validate your XML documents for well-formedness and structural correctness using this browser-based tool.
Step 1
Navigate to the XML Validator from the tool registry. The interface presents a clear input area for your XML content along with validation status indicators.
Step 2
Copy your raw or formatted XML and paste it into the input area. The tool begins analyzing the structure immediately upon input.
Step 3
The validator displays real-time results showing whether your XML is well-formed. Any errors are highlighted with line numbers and detailed descriptions.
Step 4
Each error message includes the exact line number and column where the issue was found, along with a description of what is wrong and how to fix it.
Step 5
Correct the highlighted errors in your XML content. The tool re-validates automatically as you make changes, confirming when the document is well-formed.
Step 6
Once validation passes, use the copy button to place the XML on your clipboard, or download it as a .xml file for use in your applications.
Consequence: A BOM before the XML declaration causes parse errors in strict validators.
Fix: Remove the BOM or ensure the XML declaration is the very first thing in the file.
Consequence: Inconsistent encoding within the document causes character interpretation errors.
Fix: Use a consistent UTF-8 encoding throughout the entire XML document.
Consequence: Undefined entities like ©right; cause parse errors unless declared in a DTD or entity block.
Fix: Define all custom entities in the document header or use numeric character references instead.
Check a syndication or configuration feed for well-formedness violations — unclosed tags, mismatched elements, and illegal characters — before a parser consumes it.
Re-validate an XML file that stopped parsing after manual edits to locate the first structural break rather than guessing from downstream failures.
Validate XML produced by a JSON-to-XML conversion to confirm the transformation emitted well-formed markup before the result is stored or transmitted.
This example verifies XML Validator's primary behavior without uploading data.
XML Validator checks your XML data for well-formedness and structural compliance, detecting syntax errors, missing tags, and invalid nesting. It ensures your XML documents conform to standard XML parsing rules before further processing or consumption.
No. All validation is performed entirely within your browser sandbox, meaning no XML data is transmitted to any external server.
Simply paste your XML content into the input area, and the tool automatically validates it in real time, displaying any errors with line numbers and descriptions.
The validator detects missing closing tags, improperly nested elements, invalid characters, missing required attributes, and XML declaration issues.
The current version focuses on well-formedness validation. DTD and XML Schema validation are planned for a future release.
The validator detects syntax errors (unclosed quotes, invalid indentation, tab characters), structural issues (duplicate keys, invalid key types), anchor/alias reference errors, and type inconsistencies. It provides line-specific error messages to help quickly locate and fix problems.
Yes. Once validation is complete, you can copy the corrected or validated XML to your clipboard using the provided copy button.
Yes. The validator only identifies errors without altering your original XML content, so you can review and fix issues manually.
Yes. Once the page is loaded, all validation logic runs entirely offline in your browser without requiring an internet connection.
Yes. You can view the full validation report in the output area, which details each error with its precise location and suggested fix.
XML Validator parses the pasted document entirely inside this browser tab; the XML source and all diagnostics never leave the device and are not uploaded, stored, or transmitted. Files and clipboard are used only on explicit user action, and the page continues to work offline after the initial load.
