どんな用途に？

GitHub Actions・Kubernetes・OpenAPI・Docker Composeなどの設定変換に使えます。

YAMLの特殊構文に対応？

YAML 1.2のサブセット（マッピング・シーケンス・スカラー・ブロック）に対応しています。

無料で使えますか？

完全無料で、変換はすべてブラウザ上で行われます。

YAML ⇄ JSON変換

インフラ・開発で頻繁に必要なYAMLとJSONの相互変換をブラウザで即座に実行できるツールです。構文エラーの可視化にも対応します。

Indent:

YAML

JSON

{
  "name": "Web Tool Lab",
  "tools": [
    "uuid",
    "json",
    "yaml"
  ],
  "features": {
    "fast": true,
    "free": true
  }
}

Practical Guide

Developer utilities for JSON, Cron, HTTP, URLs, UUIDs, subnets, and other checks that come up repeatedly during development and operations. Designed for quick validation before opening heavier tools.

When this tool is useful

YAML ⇄ JSON変換 helps with common Developer Tools tasks that require quick checking, conversion, or creation. It supports workflows such as YAMLとJSONの双方向変換, インデント幅（2/4スペース）切替 without forcing users to switch pages or apps.

Processing and privacy

Your input is processed in the browser and is not designed to be sent to a server just to use the tool. This makes it suitable for temporary checks, draft work, and pre-publication cleanup.

Workflow tip

After checking the result, use the related tools and same-category links near the bottom of the page to continue the surrounding task. Frequently used tools also appear in the Recently Used section.