What is .yaml?

YAML (YAML Ain't Markup Language) is a human-readable data serialization standard that can be used in conjunction with all programming languages. It is often used for configuration files and in applications where data is being stored or transmitted.

This quick guide explains when to use .yaml files, how to open them on any device, and how to share them instantly with FileXhost.

When to use .yaml files

You are configuring infrastructure tools like Kubernetes, Docker Compose, or Ansible.
You are setting up CI/CD pipelines (GitHub Actions, GitLab CI).
You need a configuration format that is easier for humans to read and edit than JSON.
You are writing frontmatter for Markdown files (like this website!).

How to open .yaml files

YAML files are plain text. You can open and edit them in any text editor (VS Code, Sublime Text, Notepad++).

Algorithm details

YAML relies on indentation (whitespace) to define structure, similar to Python. It supports scalars (strings, numbers), lists (sequences), and dictionaries (mappings). It is a superset of JSON, meaning valid JSON is also valid YAML.

Browser & platform support

Direct: Browsers display it as plain text.
Parsing: Browsers cannot parse YAML natively into objects (unlike JSON); a JavaScript library like `js-yaml` is required.

Format comparison

Feature	Details
Readability	Designed to be the most human-readable data format. Less visual clutter than JSON (no braces/quotes).
Comments	Supports comments (`#`), which JSON does not.
Complexity	More complex parser than JSON. Indentation errors can be tricky to debug.

How to create yaml files

Text Editor: Save file as 'config.yaml'.
Conversion: Convert from JSON using online tools.

How to convert yaml files

To JSON: `yq` command line tool or online converters.
FileXhost: Upload to share configuration snippets.

Advantages & disadvantages

Advantages

Clean and easy to read
Supports comments
Standard for modern DevOps tools
Can handle complex data structures (anchors and aliases)

Disadvantages

Whitespace sensitivity can cause errors
Parsing is slower and less secure than JSON (if not handled correctly)
Ambiguity in type detection (e.g., 'no' can be interpreted as boolean false in older parsers)

Tools & software

Editors

VS Code (with YAML extension), IntelliJ IDEA

CLI

yq (YAML processor)

Validation

YAMLLint

Frequently asked questions

Should I use .yaml or .yml?

Both are acceptable and mean the same thing. `.yaml` is the official recommended extension, but `.yml` was common in the DOS era (3-letter limit) and sticks around.

Is YAML better than JSON?

For configuration files written by humans, yes (due to comments and readability). For API responses, JSON is better (safer and faster to parse).

Why does my YAML fail?

The most common reason is using tabs instead of spaces for indentation. YAML forbids tabs.

Technical specs

File type: Code
Extension: .yaml
MIME type: text/yaml, text/x-yaml, application/x-yaml
Compression: Uncompressed
Max file size on FileXhost: Up to 25 MB per file on the free plan and up to 1 GB on Pro FileXhost accounts.

Upload your .yaml file to FileXhost to get a clean, shareable URL in seconds. View the file in a modern browser, protect access with optional settings, and let others download it without any confusing ads or cluttered file pages.

Upload .yaml file