JSON vs XML vs YAML vs CSV: When to Use Eac...

JSON, XML, YAML, and CSV all store structured data as text, but they are good at different things. This guide shows the same data in each format and gives a clear rule for picking one.

The same data, four ways

Here is one user record in each format.

JSON

{
  "name": "Ada",
  "roles": ["engineer", "author"],
  "active": true
}

XML

<user>
  <name>Ada</name>
  <roles>
    <role>engineer</role>
    <role>author</role>
  </roles>
  <active>true</active>
</user>

YAML

name: Ada
roles:
  - engineer
  - author
active: true

CSV (flattened — CSV can't nest)

name,roles,active
Ada,"engineer,author",true

Strengths and trade-offs

Format	Best at	Watch out for
JSON	APIs, config, nested data; universal parser support	No comments; can feel verbose
XML	Documents, mixed text + markup, formal schemas	Heaviest syntax; verbose
YAML	Config a human edits by hand; supports comments	Whitespace-sensitive — easy to mis-indent
CSV	Flat, tabular data; opens in any spreadsheet	No nesting, no real types — all text

How to choose

Building or consuming an API? Use JSON. It's the default for a reason: every language parses it and it maps cleanly to code.
Writing config a human edits often? YAML is friendlier (comments, less punctuation) — just mind the indentation.
Working with documents or systems that require a schema? XML still fits document-shaped, mixed content.
Moving flat rows in and out of spreadsheets? CSV is the simplest, as long as your data has no nesting.

A good instinct: if a program produces or consumes the data, lean JSON; if a person hand-edits it, lean YAML; if it's a table, lean CSV.

Converting between them

You rarely have to rewrite data by hand. DevUtilsNow has focused converters — CSV to JSON, JSON to CSV, and YAML to JSON — all running in your browser.

Learn more

For a deeper look at JSON itself — its types and syntax rules — see The Complete Guide to JSON.

Try it

Paste JSON to format and validate it, or use one of the converters above to move between formats — everything runs locally, nothing is uploaded.

JSON vs XML vs YAML vs CSV: When to Use Each