YAML/JSON変換

This converter transforms YAML into JSON and JSON into YAML, in both directions. Pick the direction, paste your input, and copy the converted result or read a clear error if the input is malformed.

Everything is processed locally in your browser, so your data stays on your device.

YAML and JSON describe the same kind of data, but with different priorities. JSON is strict and compact, which suits APIs and machines; YAML is indentation-based and easier for people to read and edit, which is why it dominates configuration files.

Each conversion parses the source first, so malformed input is caught and reported with the reason and often the line, instead of silently producing a broken result. A successful conversion therefore also tells you the input was valid.

It uses the YAML 1.2 and 1.1 compatible parser from js-yaml, covering the features you meet in practice: mappings, sequences, scalars, anchors and multi-line strings.

This is exactly the glue you need around CI pipelines, Kubernetes and Docker Compose files, and APIs that speak JSON while your config is written in YAML. It lets you move between the two without hand-editing.

One thing to know: YAML comments are dropped, because JSON has no concept of comments, and converting back generates fresh YAML without them.