YAML Input
Output
Tree view will appear here...
About This Tool
YAML Viewer is an essential tool for anyone working with YAML configuration files in modern DevOps, cloud infrastructure, and application development. I use this daily when debugging Kubernetes manifests, Docker Compose files, GitHub Actions workflows, Ansible playbooks, and various config files. The interactive tree view makes it easy to understand complex nested structures at a glance—expand/collapse nodes to focus on specific sections, see data types clearly (strings, numbers, booleans, arrays, objects), and quickly navigate large YAML files without getting lost in indentation. The JSON conversion feature is incredibly useful for validating YAML syntax and seeing how the data will be interpreted by parsers. Syntax validation catches errors before deployment—missing colons, incorrect indentation, invalid anchors, or malformed arrays are highlighted with precise line and column numbers.
How to Use
Paste or upload your YAML content into the input panel. The tool automatically parses and validates the YAML in real-time. Use the view mode tabs to switch between Tree View (interactive hierarchical visualization), JSON (see YAML converted to JSON format), and YAML (formatted and validated YAML output). In Tree View mode, click on any node to expand/collapse nested structures—use 'Expand All' and 'Collapse All' buttons for quick navigation of large files. Any syntax errors are displayed prominently with detailed error messages including line and column numbers. You can upload YAML files directly (supports .yaml, .yml, and .txt extensions), and the file name is displayed for reference. Copy the JSON or formatted YAML output to clipboard, or download the converted data.
Common Use Cases
Kubernetes Debugging
Paste complex K8s deployment YAML and use tree view to verify nested spec.containers.env variables, volume mounts, or resource limits structure.
Docker Compose Validation
Check docker-compose.yml syntax before running 'docker-compose up'—catch indentation errors or invalid service configurations.
GitHub Actions Review
Visualize complex workflow YAML with multiple jobs and conditional steps in an easy-to-navigate tree structure.
Config File Analysis
Parse large application configuration files (Helm charts, Ansible playbooks, OpenAPI specs) to understand the structure without reading hundreds of lines.
YAML to JSON Conversion
Convert YAML config to JSON for use with tools that only accept JSON input (many APIs and CLI tools).
Learning YAML
Use the tree view to understand how YAML indentation maps to nested data structures and how YAML anchors/aliases work.
Limitations & Important Notes
Very large YAML files (>5MB) may cause browser performance issues—for massive files, use command-line tools like yq or yaml-lint. The tool uses JavaScript YAML parser which follows YAML 1.2 spec—some YAML 1.1 features may parse differently. Custom YAML tags (!include, !env, !ref) are not supported as these are preprocessor features requiring external file access. Comments in YAML are preserved in the input display but not included in JSON/tree output (JSON doesn't support comments). For Kubernetes-specific validation (CRD schemas, API versions), use kubectl --dry-run instead. Multi-document YAML files (separated by ---) show only the first document—split multi-doc files for individual viewing. Binary data in YAML (base64 encoded) is shown as-is without decoding.