THE FILE FIELD GUIDE

.yaml

YAML Config

Web & Development

YAML uses indentation to represent structured data/settings. Whitespace and scalar interpretation matter. Version/parser differences can change values, so check the consuming application.

What it is used for: Readable settings and structured data
What the file contains: Text

All sections, questions and sources

Content reviewed：2026-10-12 · Editor：Kai

Opening steps

Choose your environment or purpose to see its steps.

Editor: inspect the structure

Make a copy before saving.

Open in an editor such as VS Code and select the appropriate language mode.
Inspect indentation, lists, keys, quotes and comments.
Inspect encoding and line endings and avoid saving as rich text.

Syntax: the target application’s parser

Check the supported YAML version and constraints.

Use the application’s documented configuration validation.
Inspect tabs, indentation, repeated keys and colon placement.
Inspect parsed types/hierarchy and revalidate after edits.

Configuration: test a small change

Separate syntax from application behavior.

Copy the settings and consult the documentation for the target key.
Apply the change in a test configuration and run validation.
Reload/restart as required and check that the intended value was used.

Menu labels and support vary by app, OS and version. Preserve the original before making changes.

Troubleshooting by symptom

Indentation error: check tabs and mismatched indentation levels.
Unexpected scalar type: check version/parser rules and quote intended strings.
Parsed but ineffective: check key names, hierarchy and application support.
Indentation error: check consistent spacing and mixed tabs.
yes/no are not strings: inspect parser/version typing and quote intended strings.
Valid syntax but failed startup: inspect required keys, types and paths.

YAML → JSON

Choose the intended YAML version/parser and read the document as data.
Save JSON separately and compare types, arrays, multiple documents and anchor handling.
Compare keys, record counts and types before/after conversion and document unsupported items.

Comments/presentation details normally disappear; custom tags or complex keys may not convert.

Preserving intended types

Consider quoting numeric/date-like values and yes/no when strings are intended; parser-version differences make type inspection important.

Anchors/aliases can reduce duplication; verify the application supports the resulting structure.

name: "example"
enabled: true
items:
  - "001"
  - "002"

Source for these steps：YAML Project · YAML revision 1.2.2

Before converting YAML to JSON

Comments and anchors do not transfer identically to JSON. Verify semantic preservation.

Validate sensitive configuration locally rather than pasting it into online validators.

Source for these steps：YAML Project · YAML revision 1.2.2

Related-format differences

Related-format differences
Format	Main role	Selection notes
YAML / YML	Indented configuration/data	Inspect typing, spacing and version
JSON	Bracketed structured data	Does not retain comments
TOML	Table-oriented configuration	Syntax and consumers differ

Handling and security

YAML may contain secrets; avoid unsafe object/tag construction and follow the application’s safe parsing guidance.

Questions and answers

Can tabs indent YAML?

Use spaces for YAML indentation.

Are YML and YAML different?

Normally they are alternative suffixes.

Do YAML 1.1 and 1.2 interpret everything identically?

No; scalar typing and other rules differ.

Are YAML and YML the same?

They generally denote the same format; use the filename required by the application.

Do backslashes in paths need care?

Escaping depends on quote style. Compare the documented example with parsed values.

Format facts: name, steward and MIME type

Formal name: YAML Ain’t Markup Language
Steward / specification: YAML language project / IETF media type registration
MIME type: application/yaml

Primary and official sources

StandardYAML revision 1.2.2
Defines indentation, scalars, sequences and mappings.
YAML Project · Link checked：2026-10-12
StandardRFC 9512 — YAML Media Type
Documents application/yaml registration and filename extensions.
IETF / RFC Editor · Link checked：2026-10-08