Bring your XML
Paste a document or open a UTF-8 file. Start with the included examples to see what valid and invalid data look like.
SMALL TOOL. LESS GUESSWORK.
Validate XML online.
Keep your data local.
Check that your XML is well-formed, find syntax errors, and format a corrected document. Your XML stays on your device.
Your data stays yours.
Default checks run in your browser. Server checks require permission.Local validation. Referral tracking is optional.
Optional saved schema library.How it works ↗
order.xml
order.xsd
XSD 1.0 local · optional advanced engines
No files selected
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READY WHEN YOU ARE
Good data starts with a quick check.
Load an example or add your own XML and schema, then run validation.
THE SHORT VERSIONA little structure.
A little structure.
A lot less debugging.
Give it a schema
An XSD defines the elements, order and data types your XML should use. Just checking the syntax? Switch to XML syntax only.
Follow the feedback
See validation errors with line numbers where available. Correct your data, check again, and export a JSON result for your records.
YOU CHOOSE THE ENGINE
Local by default. Server by permission.
Default XSD 1.0 validation and formatting run on your device with libxml2 and WebAssembly, up to 10 MB per XML document and 1 MB per schema. Local projects support 100 schemas and 10 MB total; save them on this device with five revisions or export a backup. Optional server modes support XSD 1.1, a second XSD 1.0 engine and ISO Schematron XPath 1.0, with up to 10 MB XML. They upload documents only after you select the consent checkbox. Request contents are not logged and temporary files are removed after processing. Pro and Team can also save complete schema projects and versions to their cloud workspace. Cloud saving uploads the schemas only when you choose to save. DTDs are blocked. Use the separate public HTTPS importer to fetch schema snapshots before validating. Read the processing details or use the API and CLI.
GROW WITH YOUR WORKFLOWOne file today.
One file today.
Your whole team tomorrow.
Keep checking individual files for free. Upgrade for batch validation, a saved schema library and a shared Team workspace.
FREE · PRO · TEAM
More flow. Less repetition.
Pro from US$19/month. Team from US$49/month.
Save two months with annual billing.
What does an XML validator check?
An XML syntax check determines whether the document is well-formed: tags must be properly nested, attribute values must be quoted, and the document needs a single root element. A document can pass these checks while still containing the wrong fields for your application. To check allowed elements, sequence and data types, use the XSD validator with the schema supplied by your integration partner.
How to validate an XML file
Open a UTF-8 XML file or paste its contents into the editor. Select XML syntax only, then choose Validate XML. Review each diagnostic and its line number when available. Fix the underlying problem and check the document again; one missing closing tag can cause later error messages too. You can export a JSON report after a validation run.
A common XML syntax error
For example, <order><item>Notebook</order> is malformed because item has no closing tag. The corrected document is <order><item>Notebook</item></order>. A literal ampersand in text must be escaped as &. A syntax check does not decide whether a price is correct or an invoice meets a business specification.
Privacy and supported input
The parser runs locally using libxml2 compiled to WebAssembly. Documents are not sent to a validation server. Each input is limited to 1 MB. This beta rejects DTD and entity declarations. If you deliberately save an XSD to a paid schema library, that schema is stored in the account; that optional action is separate from local XML validation.