XML Validator for API Responses
Validate XML structure and check for unclosed tags. Free browser tool — no signup.
Quick Answer
Paste XML to validate its structure: check for unclosed tags, mismatched elements, and report element and attribute counts.
How to Use the XML Validator for API Responses
- Use the input area to provide your data.
- The tool processes it instantly in your browser.
- Copy or download the result.
Frequently Asked Questions
- How do I format an API response?
- Copy the JSON response body from your API client (Postman, cURL, browser DevTools), paste it here, and click the action button to process it instantly.
- What is the difference between valid and well-formed XML?
- Well-formed XML follows syntax rules (matching tags, proper nesting). Valid XML is well-formed AND matches a specific schema (DTD or XSD). This tool checks well-formedness — the foundational requirement.
About This Tool
Working with REST APIs, GraphQL endpoints, and webhooks means constantly processing XML response data. Raw API responses are typically minified — stripped of all whitespace and line breaks to minimize payload size — making them virtually impossible to read without formatting. This tool transforms those compact responses into well-structured, readable output that reveals the data hierarchy and makes it easy to locate specific values. Paste a response from Postman, cURL, browser DevTools Network tab, or any API client, and instantly see the formatted result. The tool validates the response structure during processing, catching malformed responses that might cause subtle bugs in your application. For developers debugging production issues, this immediate visibility into API data structures is invaluable.
What is XML Validator?
An XML validator checks whether your XML document is well-formed according to the XML specification. Well-formed XML requires every opening tag to have a matching closing tag, tags to be properly nested (no overlapping), elements to use consistent naming, and special characters to be properly escaped. Validation is essential before processing XML in applications, sending SOAP requests, deploying XML configuration files, and processing data feeds. This tool identifies specific structural issues: mismatched tags, unclosed elements, and nesting problems, along with reporting the number of elements and attributes found in the document.
How to Use This Tool
- Paste your XML.
- Click Validate XML.
- See whether the document is well-formed or has issues.
- Review the specific errors or structural information.
Common Use Cases
- Formatting raw API response bodies for debugging
- Processing webhook payloads for analysis
- Cleaning up GraphQL query responses
- Inspecting third-party API data structures
Examples
<?xml version="1.0"?><catalog><book id="bk101"><title>XML Guide</title><price>9.99</price></book></catalog>
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