XML Validator
Check XML well-formedness — root element and error details
XML Input
Root element: · elements total
XML Validator — Complete Guide & Instructions
MakeCard XML Validator checks whether an XML document is well-formed using the browser's own DOMParser engine. Valid documents report the root element name and total element count; invalid ones surface the actual parser error lines so you can pinpoint unclosed tags, bad entities or missing roots. It is a fast sanity check for developers editing sitemaps, SOAP payloads, config files and RSS feeds — no upload, no IDE required.
How to Use XML Validator
- 1 Paste your XML into the "XML Input" box — or press "Sample" for a valid demo.
- 2 Click "Validate XML" to run the check.
- 3 A green "Valid XML" badge shows the root element name and total element count.
- 4 A red "Invalid XML" badge shows the first parser error lines — use them to locate the problem.
- 5 Fix the markup and validate again until it passes.
Key Features & Capabilities
- Real well-formedness checking via the browser DOMParser.
- Reports root element name and total element count on success.
- Shows actual parser error text for failures — not just "invalid".
- One-click sample for instant testing.
- Catches unclosed tags, bad nesting, unescaped entities and missing roots.
- Fully client-side — validates without any server round-trip.
Supported Formats & Specifications
| Parameter | Specification |
|---|---|
| Engine | Browser DOMParser (application/xml) |
| Valid result | Root element name + total element count |
| Invalid result | First lines of the parser error |
| Checks | Well-formedness — structure, entities, single root |
| Not covered | DTD/XSD schema validation (well-formedness only) |
Practical Everyday Use Cases
- Checking a hand-edited sitemap.xml before submitting to search engines.
- Validating SOAP envelopes or API payloads during debugging.
- Catching typos in AndroidManifest, pom.xml or app.config files.
- Verifying RSS/Atom feed markup after a template change.
- Quick sanity check before XML goes into a parser-dependent pipeline.
Pro Tips for Best Results
- Unescaped & is the most common XML error — write & inside text and attributes.
- A document needs exactly one root element — multiple top-level tags always fail.
- This checks well-formedness, not schema validity — use an XSD validator for strict structure contracts.
- Error messages name the line — count lines in your editor to find the fault fast.
Common Problems & Solutions
Invisible characters or a BOM at the file start can break parsing — retype the first line or strip hidden characters.
Only & < > " ' are predefined in XML — HTML entities like must be written as numeric character references.
Well-formedness ≠ schema-valid. The structure can be perfect XML yet violate an XSD — use a schema validator for that check.
Privacy & Security
100% Client-Side Execution
Validation runs entirely in your browser — the XML is parsed locally and never uploaded or stored.
Frequently Asked Questions
Everything you need to know about using XML Validator
Paste it into the box and press "Validate XML" — the tool parses it and reports either a green valid result with the root element, or the actual parse error.
One root element, properly nested and closed tags, quoted attribute values, and escaped special characters (& < >). Well-formedness is the minimum requirement before any parser accepts the document.
Well-formed XML follows syntax rules. Valid XML additionally matches a declared schema (DTD or XSD) defining which elements and attributes are allowed. This tool checks well-formedness.
Because & starts an entity reference — a bare ampersand is a syntax error. Write & for a literal &, or use a CDATA section for raw text.
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