Convert YAML to XML

Convert YAML to XML in your browser: load your YAML, choose XML as the target, and download the result. The converter reports exactly what it could not carry across, and nothing is uploaded to a server.

Convert YAML to XMLRuns in your browser. Nothing uploaded.

When you need this

Migrating configuration into a system that predates YAML — an application server, a build tool with an XML descriptor, an integration that will only accept a schema-validated document. In practice this is two conversions, and knowing that explains most of the surprises.

How to convert YAML to XML

Load your YAML: Drag the .yaml or .yml file in from the repository you are working in. Indentation is preserved exactly as written, so a paste from a terminal works too. Nothing leaves your browser at this or any later step.
Choose the target format: Press Ctrl+Shift+K (Cmd+Shift+K on a Mac) to open the conversion panel, then pick XML as the target. The source and the result sit side by side.
Read the loss report: The panel shows whether the conversion is lossless for your particular data, and lists every value it had to transform. Adjust indentation, key sorting and null handling if you need to.
Take the XML: Download the .xml file, copy it, or open it as a new tab to keep working on it in the XML views.

What survives the conversion

YAML to XML cannot be lossless, because the two formats express different things. Inherits every JSON-to-XML limitation, and anchors are expanded first.

Anchors are expanded before anything else happens, so a shared block appears in full at each use site in the XML.
Every JSON-to-XML limitation applies, because YAML is read into the same data model first: one root element, no array type, and element names rewritten where a key is not a valid XML name.
YAML types with no XML equivalent — dates, explicit tags like !!binary — are written as their string forms.

A worked example

A YAML sequence, expanded into repeated elements:

hosts:
  - alpha
  - beta

YAML in

<root>
  <hosts>alpha</hosts>
  <hosts>beta</hosts>
</root>

XML out

Privacy

The conversion runs in your browser — in a Web Worker for anything above a quarter of a megabyte, so the page stays responsive. Your data is not uploaded, not logged and not stored. There is no account, and the whole thing works offline.

Convert YAML to XML

Questions

Is this different from converting YAML to JSON and then to XML?

No, and it is worth being clear about that: YAML is parsed into the same in-memory structure JSON produces, then written as XML. Doing it in one step saves you a file, not a category of loss — the caveats are the union of both conversions.

Is converting YAML to XML lossless?

No, and no tool can make it so. Inherits every JSON-to-XML limitation, and anchors are expanded first. The converter lists every affected value rather than silently dropping it.

Is my YAML uploaded to a server?

No. The file is read and converted by your browser. Nothing about its contents is sent anywhere, which you can verify in your browser’s network panel or by using the tool with the network disconnected.