YAML to XML Converter
Convert YAML data to XML format with indentation and XML declaration options
Input YAML Data
Conversion Results
Enter YAML data to convert
About YAML to XML Converter
Convert YAML files and data to XML format with our free online YAML to XML converter. Transform human-readable YAML into structured XML documents with proper element nesting and valid, escaped element names.
Why use a YAML to XML Converter?
YAML excels at configuration and human readability, while XML is essential for many enterprise systems, web services, and data interchange formats. Our converter bridges these formats, enabling seamless integration between YAML-based configurations and XML-dependent systems.
Who is it for?
Perfect for developers working with SOAP services, system integrators connecting YAML configs to XML-based systems, DevOps engineers transforming configurations, API developers building XML responses, and anyone needing to convert between these popular data formats.
How to use the tool
Paste your YAML content into the input field or upload a YAML file
Choose the indentation (2, 4 or 8 spaces, or none; elements stay one per line) and whether to include the XML declaration
Choose how null values are written: an empty element, or an element marked xsi:nil="true"
The root element is always <root>, and every key becomes a child element
Toggle the XML declaration on or off
The XML output updates automatically as you type or change options
Copy the result or download as an XML file
Frequently Asked Questions
How do I convert YAML to XML online?
Paste YAML text, upload a .yaml/.yml file, or load from a URL. The converter parses the YAML and emits well-formed XML 1.0: mappings become elements with child elements per key, sequences become repeated child elements, scalars become text content. The output always has exactly one root element, named <root> (the name is not configurable); a top-level list becomes <item> children of <root>. Keys that are not valid XML names are renamed and a warning lists them. Copy or download as .xml. Conversion runs entirely in your browser — your data never leaves the device. Useful when interfacing with legacy XML-based systems from YAML-native sources.
Does converting YAML to XML preserve the data structure?
Mostly — both formats support nested hierarchical data. YAML mappings map to XML elements, sequences map to repeated child elements, scalars become element text content. What's lost: YAML comments (XML has comments via <!-- --> but they're rarely preserved in conversion), anchors and aliases (resolved to inline values before output, so the XML is self-contained), and YAML's specific scalar types (XML treats everything as text by default). What XML adds beyond YAML: attribute support (this converter always writes elements, never attributes), namespaces, mixed content.
Which YAML rules and limits apply?
Only strict, single-document YAML 1.2 is read. A duplicate key in one mapping is an error, not a silent overwrite. Input with a second document after a --- separator is rejected with an error, so convert multi-document files one document at a time. Core typing applies: 012 loads as the number 12 (leading zeros are lost unless the value is quoted in the YAML) and yes/no stay plain strings. Nesting deeper than 100 levels is rejected. Aliases are expanded before conversion, and a document is refused if an anchor refers to itself or alias expansion grows past 1,000,000 nodes or about 50 million characters of output (both limits scale up with unusually large inputs).
How are null and empty YAML values written in XML?
YAML has ~ and null for missing values. With the default "Empty element <x/>" setting, those, an empty string, an empty mapping ({}) and an empty sequence ([]) all become the same empty element <x/>, so the XML cannot tell them apart. Choosing the xsi:nil="true" option marks only the null values (~ and null) as <x xsi:nil="true"/>, including null items in a sequence, and declares xmlns:xsi on the <root> element when at least one was written; an empty string, mapping or sequence is still <x/>. Our XML to JSON tool reads xsi:nil="true" back as an attribute (@_xsi:nil with the value true), not as null, so this does not round-trip. Element names are limited to the XML 1.0 (4th edition) name characters so that parsers built on expat accept the file; any other character, including emoji, becomes _ (a😀b is written as a_b), a key that is not a valid name gets a _ prefix, and names that collide after renaming get _2, _3 suffixes. Renamed keys are listed in a warning.
Can I upload a YAML file or load it from a URL?
Yes — all three input methods: paste YAML text, upload a local .yaml or .yml file, or fetch from a public URL. URL fetching requires the source to send CORS headers. For private files, download locally first. Files up to several MB convert quickly client-side.
Is my YAML data sent to a server when I convert?
No. Conversion runs in your browser via JavaScript. Your YAML never reaches a server, never gets logged. Verify in DevTools' Network tab: converting produces zero HTTP requests. The exception is URL loading, where your browser fetches the source from the URL you provided (the URL host sees that request, but no Toolsana server is involved). Safe for sensitive configuration including secrets and credentials.
How are YAML sequences represented in XML?
YAML sequences become repeated child elements with the same tag name. tags: [a, b, c] becomes <tags>a</tags><tags>b</tags><tags>c</tags>. The sequence boundary is implicit — when consuming the XML, you can't tell 'a single tags element' from 'a sequence containing one element'. Lists nested directly inside lists use <item> elements. If your XML consumer expects wrapper elements, post-process the output or use a XSLT transform.
Feeding YAML configuration into a legacy XML-based system?
Common workflow: maintain configuration in modern YAML (easier for humans), convert to XML at deployment time for the legacy consumer. For one-off bridging or troubleshooting, the manual tool is fast. For ongoing pipelines, automate the conversion in your own scripts. For the reverse direction (legacy XML → modern YAML), use [XML to YAML](/tools/xml-to-yaml/). For data interchange in modern systems, prefer JSON via [YAML to JSON](/tools/yaml-to-json/) instead — JSON is faster, smaller, and more widely supported.
How much data can I convert at once?
Browser memory is the limit. XML output is typically 2-4x the source YAML size (opening/closing tags add significant overhead). Up to ~5 MB YAML produces ~15 MB XML, converting in 1-2 seconds. Past 20 MB output, the browser may slow or run out of memory. For very large files, split the YAML into smaller pieces. This tool fits the common case of converting small-to-medium config files.
When is YAML→XML conversion the right choice in 2026?
Only when the consumer requires XML. Legacy enterprise systems (older SOAP services, EDI gateways, healthcare HL7, government data feeds) often accept only XML. For these targets, YAML-then-XML conversion is the bridge. For greenfield development, JSON is the modern default — smaller, faster, native everywhere. Convert via [YAML to JSON](/tools/yaml-to-json/) instead. XML's strengths (XSD validation, namespaces, mixed content) matter mostly for document-centric use cases; for data interchange, JSON typically wins.
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