Format guide
What is XML?
Extensible Markup Language is a strict tag-based markup language for hierarchical documents and data exchanges, created by W3C (1998). XML powers feeds, office document internals, SVG, and enterprise integrations that need namespaces and schemas. Newer public APIs often prefer JSON, but XML remains essential where standards and documents demand it.
XML format specifications
- Full name
- Extensible Markup Language
- Kind
- structured data
- File extension
- .xml
- MIME type
- application/xml
- Developer / standard
- W3C · 1998
- Compression
- none or container
- Quality model
- Lossless / not lossy
- Container
- No / single bitstream typical
- Common codecs
- —
- Technical sources
- —
- Transparency
- Not supported
- Animation
- No (still / non-animated typical use)
- Typical size
- Larger than equivalent JSON due to closing tags
- Browser support
- Parsable in-browser; not a general end-user document format except SVG/XHTML cases
- Compatibility
- Mature parsers everywhere; browser DOMParser available
XML compression & quality
XML compression: none or container. Lossless (or non-destructive packaging) keeps reconstructable data — size savings come from packing efficiency, not throwing detail away. Typical size profile: Larger than equivalent JSON due to closing tags. Quality note: Excellent for structured documents; verbose on the wire
Quality: Excellent for structured documents; verbose on the wire
Typical size: Larger than equivalent JSON due to closing tags
Transparency & animation
XML does not support an alpha channel. Convert to PNG, WebP, AVIF, or SVG when you need transparent backgrounds.
XML is a still-media or non-animated format in typical use. Use GIF, APNG, video, or animated WebP when you need motion.
XML metadata
Usually none beyond encoding/BOM — structure is the content. Comments allowed in YAML/TOML.
Best use cases for XML
- RSS/Atom and sitemaps
- Office Open XML internals
- SVG source
- Regulated B2B payloads
- Publishing pipelines with XSLT
When to avoid XML
- Greenfield JSON-only public APIs
- Hand-editing massive trees
- Mobile bandwidth-sensitive chatty APIs
- Simple config better expressed as TOML/JSON
Advantages
- Schemas and namespaces
- Mixed content for documents
- Battle-tested enterprise tooling
- Human-inspectable text
Disadvantages
- Verbose
- Attribute vs element modeling complexity
- Heavier parsing than JSON
- XXE risks if parsers are misconfigured
Compatibility
Mature parsers everywhere; browser DOMParser available
Browsers: Parsable in-browser; not a general end-user document format except SVG/XHTML cases
Software support
- Oxygen XML
- VS Code
- libxml tooling
- Office apps
- Format Convertly
Device support
- Servers and desktops in enterprise stacks
- Modern desktops
- Phones and tablets with compatible apps
How to open XML
Open in a code editor or XML IDE. For data interchange, validate against the expected XSD when one exists.
How to convert XML
Convert XML to JSON for modern APIs or keep XML when a standard requires it — Format Convertly handles private in-browser conversion for supported paths.
Popular XML conversions
Convert to XML
Incoming conversions strengthen the XML cluster — e.g. JPG → XML, PNG → XML.
XML comparison guides
Compare XML with related formats to pick the right container for quality, size, and compatibility.
Best format guides featuring XML
Decision pages that cite XML — the next hop after a vs comparison.
Related formats
XML tools
Tools extend the format graph beyond one-off conversion — compression, metadata, and utilities for real workflows.
Technical sources
XML FAQ
What is a XML file?
XML is a strict tag-based markup language for hierarchical documents and data exchanges. XML powers feeds, office document internals, SVG, and enterprise integrations that need namespaces and schemas. Newer public APIs often prefer JSON, but XML remains essential where standards and documents demand it.
Is XML lossy or lossless?
XML is typically lossless or non-destructive in common use (none or container).
Does XML support transparency?
XML does not support an alpha channel. Convert to PNG, WebP, AVIF, or SVG when you need transparent backgrounds.
How do I open a XML file?
Open in a code editor or XML IDE. For data interchange, validate against the expected XSD when one exists.
How do I convert XML privately?
Convert XML to JSON for modern APIs or keep XML when a standard requires it — Format Convertly handles private in-browser conversion for supported paths. Format Convertly keeps processing in your browser so files are not uploaded to a conversion server.
Are my XML files uploaded on Format Convertly?
No. XML conversion runs in your browser. Files are not sent to Format Convertly servers for processing.