Free YAML Tools
Validate, convert, format, and edit YAML in your browser. All free, no login required, with copy, download, and share built in.
What can these tools do?
Validate YAML syntax with line-and-column error messages, convert between YAML and JSON, format and sort keys, and edit YAML with autosave. Every tool is free, browser-based, and processes your data locally with no server upload.
Tools
YAML Validator
Validate YAML syntax instantly. Spot errors with line and column numbers, see detailed messages, and confirm files are well-formed before deployment.
YAML to JSON
Convert YAML to JSON in your browser. Supports anchors, aliases, multiline strings, and nested structures. Copy, download, or upload files.
JSON to YAML
Convert JSON to YAML with custom indentation and key sorting. Safe in-browser conversion, no data leaves your device.
YAML Formatter
Format and beautify YAML. Choose 2 or 4 space indentation, sort keys alphabetically, and produce consistent, diff-friendly output.
YAML Editor
Edit YAML in the browser with live validation, syntax highlighting, and localStorage autosave. No signup required.
YAML Guide
Complete plain-English YAML guide. What YAML stands for, file format, syntax rules, and how it compares with JSON and XML.
YAML Topic Guides
Quick-reference pages for the most common YAML questions and gotchas.
YAML Comments
Add single-line and multiline comments in YAML files. Covers the # syntax, gotchas, and tool-specific behavior.
YAML Multiline Strings
Block scalars in YAML: literal (|), folded (>), chomping indicators, and how to embed newlines and special characters cleanly.
YAML vs JSON
Detailed YAML vs JSON comparison: syntax, comments, file size, parser support, and when to choose each.
YML vs YAML
Are .yml and .yaml the same? Complete answer with history, tool support matrix, and recommendations.
ModuleNotFoundError: No module named 'yaml'
Fix the Python ImportError when 'yaml' is missing. Covers pip install pyyaml, virtual environments, Conda, and macOS path issues.
YAML in Python (PyYAML Guide)
Read, write, and manipulate YAML in Python with PyYAML. Covers safe_load, dump, ruamel.yaml, common errors, and best practices.
YAML Arrays, Lists, and Dictionaries
Block and flow sequences, nested lists, lists of maps, and YAML dictionaries explained with copy-ready examples.
YAML Anchors, Aliases, and Merge Keys
Reuse YAML data with anchors (&), aliases (*), and merge keys (<<:). Avoid duplication across environments and Compose services.
Kubernetes YAML: Deployments and Manifests
Anatomy of Kubernetes Deployment, Service, ConfigMap, and Secret manifests with copy-ready YAML examples and common errors.
YAML Syntax Reference
Complete YAML 1.2 syntax reference: scalars, sequences, mappings, indentation rules, comments, anchors, multiline, and full examples.
Docker Compose YAML Guide
Service definitions, networks, volumes, env_file, depends_on, profiles, and anchor reuse in docker-compose.yml and compose.yaml.
Why use our YAML tools?
YAML is everywhere: Kubernetes manifests, GitHub Actions workflows, Docker Compose files, Ansible playbooks, OpenAPI specs, and CI config across every major platform. A small indentation slip can break a deployment, so a fast and accurate YAML toolchain matters.
- Zero friction - every tool works instantly in your browser with no signup or installation
- Line-and-column errors - the validator and converters surface exact error positions, not vague messages
- Privacy-first - YAML parsing happens in your browser; your data never reaches a server
- Autosave - the editor persists drafts to localStorage so you never lose work
- YAML 1.2 compliant - handles anchors, aliases, merge keys, block scalars, and tagged values
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