xml-formatter

Paste any XML — an App.config, a SOAP envelope, an MSBuild project file — to validate, pretty-print, or minify it. Parse errors point to a line and column where the browser's own parser caught them.

client-side only line & column errors no signup
input.xml
Paste XML on the left and click Format, Minify, or just start typing to validate.

// what gets checked

// format vs. minify

Formatting re-indents nested elements, keeps attributes on the opening tag, collapses genuinely empty elements to self-closing tags, and leaves comments, <![CDATA[...]]> sections, and the <?xml ... ?> declaration untouched. Minifying strips all the whitespace between tags down to a single line — useful before storing XML in a database column or shipping it over the wire — while leaving whitespace that's part of an element's actual text content alone.

// where this shows up in .NET

App.config and Web.config, MSBuild .csproj/.props/.targets files, WCF/SOAP payloads, NuGet's nuget.config, and XAML all lean on hand-edited XML, so a stray missing closing tag or an unescaped & in a connection string is a common source of the "configuration system failed to initialize" class of startup errors — this tool exists to catch that before it hits a build or a running process.