XML Formatter

Machine-generated XML almost never has line breaks. SOAP envelopes, RSS feeds, sitemaps, Android layouts pulled from a build, and configuration exported by a tool all tend to arrive as a single continuous line, which is unreadable and hides the nesting entirely.

Formatting adds the indentation back so the tree structure becomes visible. That is usually enough on its own to spot the problem you opened the file for: a mismatched tag, an element at the wrong depth, or a section that repeated when it should not have.

XML is stricter than HTML in ways that surprise people coming from the web. Every tag must be closed, tags are case sensitive so Item and item are different elements, and every attribute value must be quoted. A browser forgives all three; an XML parser does not.

Five characters have to be escaped in text content: ampersand, less than, greater than, and both quote marks. An unescaped ampersand is the most frequent cause of a document that looks fine and fails to parse, and it usually arrives inside a URL with query parameters.

There can be exactly one root element. Concatenating two valid XML documents produces an invalid one, which is a common surprise when stitching together output from a loop.

Formatting and validation run locally. XML payloads tend to carry exactly the sort of content you should not paste into someone else's server: invoices, patient records, financial messages, and internal service traffic. None of it is uploaded here.