YAML to JSON Converter — Convert YAML Online

YAML uses indentation (whitespace) to represent hierarchy. Objects are written as key: value pairs on separate lines; arrays use dash prefixes (- item). Comments start with # and are preserved in the YAML source but dropped during JSON conversion because JSON has no comment syntax. JSON uses curly braces for objects, square brackets for arrays, and requires all strings to be double-quoted. JSON supports no comments. Both formats represent the same primitive types: strings, numbers, booleans (true/false), null, objects, and arrays. The primary practical difference is that YAML is easier to write by hand and supports comments, while JSON is more universally supported by APIs, databases, and programming language libraries.

YAML supports anchors (&name) and aliases (*name) that allow you to define a value once and reference it multiple times, reducing repetition. For example: defaults: &defaults adapter: postgres host: localhost — then development: <<: *defaults database: dev_db reuses the anchor. When converting to JSON, anchors are resolved: the alias is replaced with the full value inline. This means the output JSON may contain repeated identical objects where the YAML had references. This is valid JSON and functionally equivalent, but the deduplication advantage of YAML anchors is lost in the JSON form.

YAML supports multiple documents in a single file, separated by --- (document start marker) and optionally ... (document end marker). Multi-document YAML is common in Kubernetes manifests, where a single file might contain a Deployment and a Service definition. JSON does not support multi-document files. When converting multi-document YAML, the converter either processes only the first document or wraps all documents in a JSON array. This tool processes a single YAML document per conversion.

Kubernetes resource definitions (Pods, Deployments, Services, ConfigMaps) are written in YAML. However, many tools and APIs that interact with Kubernetes — including the Kubernetes API itself — accept or return JSON. Converting your YAML manifests to JSON lets you inspect them with JSON tools, submit them to the API directly, or use jq for querying and transformation. Docker Compose files are YAML-based and can also be inspected in JSON form for debugging. When troubleshooting a Kubernetes deployment, converting the manifest to JSON and using a JSON schema validator can catch type errors (e.g., a number serialized as a string) that are invisible in YAML.

GitHub Actions workflows, CircleCI configs, GitLab CI/CD pipelines, and Azure Pipelines all use YAML. If you need to programmatically generate or validate these configs (for example, in a templating system), converting them to JSON first lets you use standard JSON manipulation libraries. You can then convert the modified JSON back to YAML for the final pipeline file. This round-trip approach — YAML → JSON → manipulate → JSON → YAML — is a common pattern in pipeline generators and GitOps automation tools.

REST APIs overwhelmingly use JSON as their request and response format. When your configuration or data source is in YAML, you need to convert it before submitting to an API. This is common when working with infrastructure-as-code tools: Terraform supports both HCL and JSON formats; AWS CloudFormation accepts both YAML and JSON templates. Converting YAML to JSON also enables direct use with JavaScript/TypeScript JSON.parse(), Python json.loads(), and similar native JSON parsers without adding a YAML dependency to your runtime environment.