YAML to JSON Converter

Why convert YAML to JSON?

YAML and JSON describe the same kind of data — objects, arrays, strings and numbers — but in different syntax. YAML is the format of configuration files: Docker Compose, GitHub Actions, Kubernetes manifests and Ansible playbooks are all YAML. JSON is the format of APIs and JavaScript: most tools that consume data expect JSON. Moving between the two is a daily task for developers and DevOps engineers, and doing it by hand is error-prone — one wrong indent in YAML changes the meaning of the whole document. This converter parses your YAML properly and emits clean, formatted JSON.

How it works

Paste YAML into the left box and the JSON appears on the right, formatted with two-space indentation. Nested maps become nested objects, lists become arrays, and YAML's plain scalars become JSON strings, numbers or booleans as appropriate. If the YAML has a syntax error, the tool reports the exact error message from the parser instead of producing wrong output — a misplaced indent or a tab character is the usual cause, since YAML forbids tabs for indentation.

Common gotchas

YAML is sensitive to indentation: two spaces per level is the convention, and mixing tabs and spaces breaks parsing. Unquoted values such as "yes", "no", "on" and "off" can be interpreted as booleans in YAML 1.1, which surprises people who meant them as strings — quote them if you mean the literal word. Multi-line strings and anchors are supported by the parser used here, so configuration files with reused blocks convert correctly.

Frequently asked questions

Is YAML a superset of JSON?

Yes — valid JSON is valid YAML, because YAML 1.2 was designed to accept JSON syntax. The reverse is not true: YAML has features such as comments, anchors and multi-line strings that JSON does not support.

Why does my YAML fail to parse?

The most common causes are tabs used for indentation (YAML requires spaces), inconsistent indentation levels, and unquoted special values. The error message above points at the line — check the indentation there first.

Does this tool upload my YAML?

No. The conversion runs in your browser using the js-yaml library loaded from a CDN. Your configuration never leaves your device, which matters when it contains hostnames, credentials or internal service names.