YAML to JSON

Parse YAML into indented JSON. Docker Compose, Kubernetes, and server configs often start in YAML.

{{ yamlToJson.message }}

Overview

YAML and JSON are close cousins in the data serialization format family — technically, JSON is a subset of YAML 1.2, meaning any valid JSON is also valid YAML. The reverse does not hold: YAML has anchors, aliases, custom type tags, comments, and significant indentation, none of which exist in JSON. That difference defines, in practice, when to use each one: YAML for configurations that humans will edit frequently; JSON for data exchanged between systems.

YAML definitively conquered the DevOps world in the 2010s. Kubernetes uses YAML for everything: Deployments, Services, ConfigMaps, Ingresses — any platform engineer today needs to read and write YAML fluently. Docker Compose, GitHub Actions, GitLab CI, CircleCI, Ansible, Helm — all chose YAML as their manifest format because it is genuinely more pleasant to read and edit than JSON for long files. The downside is that YAML was designed to be edited by humans, not parsed by machines at scale — and YAML parsing libraries have a well-documented history of vulnerabilities, especially in languages that allow arbitrary type deserialization.

Converting YAML to JSON is necessary when you need to use data from a YAML configuration in a context that only accepts JSON: REST APIs, JSON Schema validation tools, structured logs, AWS Lambda configurations that expect JSON, Grafana dashboards, or simply debugging a complex YAML structure with a more familiar visualization. YAML with anchors and aliases is particularly useful for reducing repetition in configuration files — but when converted to JSON, those references are expanded, resulting in more verbose but fully explicit JSON.

This tool uses a YAML parser loaded on demand in the browser. Advanced YAML with custom type tags or very deep anchors may behave differently across implementations — the parser used here is js-yaml, widely adopted in the JavaScript ecosystem. For most use cases — Kubernetes manifests, Docker Compose, GitHub Actions, framework configurations — the result is reliable. Validate critical outputs before using in automation.

Technical deep dive

Common questions summarized

  • What is this tool for?: It runs fully in your browser: useful to validate, format, or convert data in everyday development.
  • Are my inputs sent to a server?: Processing happens locally with JavaScript. We do not store what you paste into the text areas.
  • Can I use this for real production data?: Use at your own risk. For secrets (passwords, tokens), prefer controlled environments and your company policies. And always review the generated contents. Never trust blindly things you see on the internet.

Sample payload to try

  • See also the larger "Code Snippets" sample; paste this excerpt to try locally: Sample — servico: porta: 8080 debug: true

Code Snippets

Code example
servico:
  porta: 8080
  debug: true

Sample

servico:
  porta: 8080
  debug: true

FAQ

What is this tool for?

It runs fully in your browser: useful to validate, format, or convert data in everyday development.

Are my inputs sent to a server?

Processing happens locally with JavaScript. We do not store what you paste into the text areas.

Can I use this for real production data?

Use at your own risk. For secrets (passwords, tokens), prefer controlled environments and your company policies. And always review the generated contents. Never trust blindly things you see on the internet.