# XML Validator — Check Well-Formedness and Structure

> Check XML is well-formed, with the exact line and column of the first error and a document summary.

An XML validator checks that a document is well-formed: every tag closed and correctly nested, exactly one root element, attributes quoted, and reserved characters escaped. This reports the first error with its line and column, and for a valid document summarises the element count, nesting depth, attributes and namespaces.

**URL:** https://convertto.tech/t/xml-validator
**Category:** Data & Format Tools (https://convertto.tech/c/data-tools)
**Privacy:** Runs entirely in the browser; no upload
**Cost:** Free, no sign-up
**Last updated:** 2026-08-01

## Key facts

- **Privacy:** Runs entirely in your browser — nothing is uploaded
- **Cost:** Free, unlimited, no sign-up

## How to use

1. Enter or paste your xml.
2. Turn "Report namespaces and attributes" on or off as needed.
3. The result appears immediately — copy or download it.

## FAQ

### Does this validate against my XSD schema?

No — browsers have no built-in schema validator, and shipping one would mean a large library for a check most people do not need. This verifies well-formedness, which is the failure that causes almost every "my XML will not parse" problem.

### My file looks fine but fails on line 1, column 1. Why?

Almost always a byte-order mark or whitespace before the XML declaration. The `<?xml ...?>` declaration must be the first bytes of the file with nothing whatsoever before it. Saving as "UTF-8 without BOM" fixes it.

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