Convert YAML to JSON
Convert YAML — GitHub Actions, Docker Compose, Kubernetes manifests — to JSON in your browser. Block scalars, flow collections and comments handled; nothing is uploaded.
Paste a YAML file and get equivalent JSON instantly: block mappings and sequences, compact - key: value items, flow collections ({a: 1, b: [2, 3]} spanning multiple lines), block scalars (| and > with chomping), quoted and plain scalars, and comments. The first document of a multi-doc file is converted.
The parser is a hand-rolled YAML subset tuned for the files developers actually convert — workflows, compose files, CI configs, Helm values. Numbers become JSON numbers, true/false/null become JSON booleans and null, and unquoted yes/no stay strings exactly as YAML 1.2 core schema says.
Unsupported YAML features are refused loudly, not silently mangled: anchors and aliases (&a / *a), explicit tags (!!str), merge keys (<<), and documents after the first all produce a clear error with the line number, so you always know what to fix.
Frequently asked questions
- Which YAML files does it handle?
- The everyday subset: GitHub Actions workflows, Docker Compose files, Kubernetes manifests, CI configs and Helm-style values — block and flow collections, block scalars, comments and quotes. GitHub Actions and Compose files in the wild fit comfortably.
- Why does my file with &anchors fail?
- Anchors/aliases, explicit tags, merge keys and later documents of a multi-doc file are intentionally refused with the exact line number — silently expanding them the wrong way would corrupt your config. Expand them first and the conversion succeeds.
- Is the conversion done on a server?
- No. The parser runs in your browser tab. Secrets in CI configs and compose environment blocks never leave your device.