JSON vs XML vs YAML
JSON, XML and YAML all do the same fundamental job: they represent structured data as text. But each has a different personality, and picking the right one makes your APIs, config files and documents easier to work with.
Here is a straightforward comparison to help you choose — and convert between them when you need to.
JSON — the default for APIs
JSON (JavaScript Object Notation) is compact, easy to parse, and supported everywhere. It maps cleanly to the data structures of almost every programming language, which is why it dominates web APIs.
Its weaknesses: no comments, and it can get hard to read when deeply nested. But for machine-to-machine communication, JSON is usually the right default.
XML — verbose but powerful
XML (eXtensible Markup Language) is older and more verbose, wrapping every value in opening and closing tags. That verbosity brings power: attributes, namespaces, schemas (XSD) for strict validation, and tooling like XPath and XSLT.
XML still rules in enterprise systems, document formats (like DOCX under the hood), SOAP web services and configuration where strict validation matters.
YAML — built for humans
YAML is designed to be read and written by people. It uses indentation instead of brackets and supports comments, which makes it the favourite for configuration — Docker Compose, Kubernetes, GitHub Actions and CI pipelines all use it.
Its main risk is that significant whitespace can cause subtle errors, so a validator is your friend. YAML is a superset of JSON, so any JSON is also valid YAML.
Which should you choose?
Use JSON for APIs and data interchange. Use XML when you need strict schemas, attributes or must integrate with systems that expect it. Use YAML for human-edited configuration files.
The good news is you are never locked in: you can convert freely between all three with the FilesSwift converters below.
Frequently asked questions
Is YAML better than JSON?
Neither is "better" — YAML is easier for humans to edit (great for config), while JSON is simpler for machines (great for APIs).
Can I convert between JSON, XML and YAML?
Yes. FilesSwift has free converters for every direction, and they preserve your data structure.
Does JSON support comments?
Standard JSON does not. YAML and XML both support comments, which is one reason YAML is popular for configuration.
Is XML dead?
No. XML remains widely used in enterprise systems, document formats and anywhere strict schema validation is required.