Online YAML Editor
Free online YAML editor with built-in schema validation for Kubernetes and GitHub Workflows. Includes multi-document support, syntax highlighting, and JSON conversion.
Features
Multi-document Support
Edit and validate multiple YAML documents in a single file
Schema Validation
Built-in schemas for Kubernetes and GitHub Workflows
Real-time Syntax Validation
Instant error detection and syntax highlighting
Smart Formatting
Auto-indentation and one-click YAML formatting
Format Conversion
Convert between YAML, JSON, and other formats
Frequently Asked Questions
What are YAML data types and how to use them?
YAML supports various data types and structures:
# Scalars (strings, numbers, booleans)
string_plain: Hello World
string_quotes: "Hello World"
number_int: 42
number_float: 3.14159
boolean: true
null_value: null
# Multi-line strings
description: |
This is a long text
that spans multiple lines
with preserved newlines
folded: >
This is a long text
that will be folded
into a single line
# Lists (sequences)
simple_list:
- item1
- item2
- item3
nested_list:
- name: first
value: 1
- name: second
value: 2
Our editor provides syntax highlighting and validation for all YAML data types.
How do I validate Kubernetes YAML configurations?
Our editor includes built-in Kubernetes schema validation:
# Deployment with resource limits
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx-deployment
labels:
app: nginx
spec:
replicas: 3
selector:
matchLabels:
app: nginx
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:1.14.2
ports:
- containerPort: 80
resources:
limits:
cpu: "1"
memory: "512Mi"
requests:
cpu: "0.5"
memory: "256Mi"
The editor validates:
- Resource types and versions
- Required fields
- Field types and formats
- Resource limits and requests
- Label selectors and references
How to work with multiple YAML documents?
Use document separators (---) to combine related configs:
# ConfigMap for application settings
apiVersion: v1
kind: ConfigMap
metadata:
name: app-config
data:
database_url: "postgresql://db:5432"
api_key: "development-key"
---
# Service for the application
apiVersion: v1
kind: Service
metadata:
name: app-service
spec:
selector:
app: myapp
ports:
- port: 80
---
# Deployment using the ConfigMap
apiVersion: apps/v1
kind: Deployment
metadata:
name: app-deployment
spec:
template:
spec:
containers:
- name: app
envFrom:
- configMapRef:
name: app-config
Features:
- Individual validation per document
- Cross-document reference checking
- Document outline navigation
- Collapse/expand documents
What schema validations are supported?
The editor supports two types of schema validation:
1. Kubernetes Resources
apiVersion: v1
kind: Service
metadata:
name: my-service
namespace: default
spec:
selector:
app: my-app
ports:
- protocol: TCP
port: 80
targetPort: 9376
2. GitHub Workflows
name: CI/CD Pipeline
on:
push:
branches: [ main ]
pull_request:
branches: [ main ]
jobs:
build:
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v2
- name: Setup Node.js
uses: actions/setup-node@v2
with:
node-version: '14'
- run: npm ci
- run: npm test
The editor automatically detects and applies the appropriate schema based on the YAML content. It provides:
- Resource validation
- Field type checking
- Required field validation
- Action/step validation for workflows
- Syntax highlighting specific to each schema
How to handle anchors and aliases in YAML?
YAML anchors (&) and aliases (*) help reduce repetition:
# Define common configurations
definitions:
- &java_container
image: openjdk:11
environment: &java_env
JAVA_OPTS: -Xmx512m
APP_ENV: prod
# Use the configurations
services:
api1:
<<: *java_container # Merge java_container
environment:
<<: *java_env # Merge java_env
API_PORT: 8080
api2:
<<: *java_container
environment:
<<: *java_env
API_PORT: 8081
Features:
- Syntax highlighting for anchors/aliases
- Validation of references
- Auto-completion for defined anchors
- Preview of resolved values
How to troubleshoot common YAML errors?
Common YAML issues and solutions:
# 1. Indentation Errors
correct:
nested:
key: value # Consistent 2-space indent
wrong:
nested: # ❌ Inconsistent indent
key: value # ❌ Wrong level
# 2. Quote Issues
correct_quotes:
simple: Hello World
special: "Hello: World"
multiline: |
Line 1
Line 2
# 3. Array Formatting
correct_arrays:
- item1
- item2
- key: value
other: value
# 4. Boolean Values
correct_booleans:
- true # Not True
- false # Not False
- yes # Alternative
- no # Alternative
The editor provides:
- Real-time error detection
- Detailed error messages
- Quick fixes for common issues
- Format on paste/save options
Where can I learn more about YAML?
Explore these official resources and learning materials:
Official Specifications:
- YAML Specification 1.2 - Complete YAML specification
- YAML Reference Card - Quick syntax reference
- YAML Official Site - Standards and documentation
Learning Resources:
- YAML Tutorial - Learn YAML in minutes
- YAML Best Practices - Ansible YAML guide
- YAML Gotchas - Common pitfalls
DevOps & Configuration:
- Kubernetes YAML - K8s configuration
- Docker Compose YAML - Container orchestration
- GitHub Actions YAML - CI/CD workflows
- Ansible YAML - Automation playbooks
These resources cover YAML from basic syntax to advanced DevOps configurations!
YAML Syntax Guide
Quick reference for YAML data types, structures, Kubernetes patterns, and common gotchas.
Basic Data Types
string_plain: Hello World\nstring_quoted: "Hello: World"\nnumber_int: 42\nnumber_float: 3.14159\nboolean: true\nnull_value: null
Scalars: strings (plain/quoted), numbers, booleans, null values
name: John Doedescription: |\n This is a literal block\n Preserves line breaks\n\nfolded: >\n This text will be\n folded into a single line
Multi-line strings: | (literal) preserves newlines, > (folded) joins lines
special_chars: "Use quotes for: colons, brackets, braces"\nno_quotes: Simple values without special characters
Quote strings containing special YAML characters like :, [, ], {, }
Lists & Mappings
simple_list:\n - item1\n - item2\n - item3\n\ninline_list: [item1, item2, item3]
Lists/sequences: block style with dashes or inline with brackets
mapping:\n key1: value1\n key2: value2\n\ninline_map: {key1: value1, key2: value2}Mappings/objects: block style with colons or inline with braces
nested_structure:\n database:\n host: localhost\n port: 5432\n credentials:\n username: admin\n password: secret
Nested mappings and lists with proper indentation
mixed_list:\n - name: John\n age: 30\n - name: Jane\n age: 25\n - simple_item
Lists can contain both mappings and simple values
Kubernetes Patterns
apiVersion: apps/v1\nkind: Deployment\nmetadata:\n name: my-app\n labels:\n app: my-app\nspec:\n replicas: 3\n selector:\n matchLabels:\n app: my-app
Basic Kubernetes resource structure with apiVersion, kind, metadata, and spec
resources:\n limits:\n cpu: "1"\n memory: "512Mi"\n requests:\n cpu: "0.5"\n memory: "256Mi"
Resource limits and requests for containers
env:\n - name: DATABASE_URL\n value: "postgresql://localhost:5432"\n - name: API_KEY\n valueFrom:\n secretKeyRef:\n name: api-secret\n key: key
Environment variables from values and secrets
Anchors & Aliases
defaults: &default_config\n timeout: 30\n retries: 3\n debug: false\n\nservice1:\n <<: *default_config\n name: API Service\n port: 8080
Anchors (&) define reusable content, aliases (*) reference it, merge (<<) combines
database_config: &db\n host: localhost\n port: 5432\n\nproduction:\n database: *db\n pool_size: 20\n\ndevelopment:\n database: *db\n pool_size: 5
Reuse configuration blocks across different environments
GitHub Actions Patterns
name: CI/CD Pipeline\non:\n push:\n branches: [main, develop]\n pull_request:\n branches: [main]\n\njobs:\n test:\n runs-on: ubuntu-latest
GitHub Actions workflow structure with triggers and jobs
steps:\n - uses: actions/checkout@v3\n - name: Setup Node.js\n uses: actions/setup-node@v3\n with:\n node-version: "18"\n cache: npm\n - run: npm ci\n - run: npm test
Action steps with marketplace actions and shell commands
strategy:\n matrix:\n node-version: [16, 18, 20]\n os: [ubuntu-latest, windows-latest]\n fail-fast: false
Matrix strategy for testing multiple versions and platforms
Docker Compose Patterns
version: "3.8"\nservices:\n web:\n build: .\n ports:\n - "3000:3000"\n environment:\n - NODE_ENV=production\n depends_on:\n - database
Docker Compose service definition with build, ports, and dependencies
volumes:\n postgres_data:\n\nservices:\n database:\n image: postgres:13\n volumes:\n - postgres_data:/var/lib/postgresql/data\n environment:\n POSTGRES_DB: myapp
Named volumes and environment variables for services
Common Gotchas
# Correct indentation\ncorrect:\n - item1\n - item2\n\n# Wrong indentation\nwrong:\n - item1 # ❌ Inconsistent\n - item2
Consistent indentation is crucial - use spaces, not tabs
# Quoted numbers\nversion: "1.2" # String\nport: 8080 # Number\n\n# Boolean values\nenabled: true # Not True\ndisabled: false # Not False
Be careful with data types - quote strings that look like numbers
# Multi-document separator\n---\ndocument1: value\n---\ndocument2: value
Use --- to separate multiple YAML documents in one file
Resources
Complete YAML specification
Quick syntax reference
K8s configuration guide
CI/CD workflow syntax
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