https://developer.mozilla.org/ja/docs/Glossary/CORS https://developer.mozilla.org/ja/docs/Web/HTTP/CORS .† CORSの仕様はなぜ複雑なのか https://zenn.dev/qnighy/articles/6ff23c47018380 CORS(Cross-Origin Resource Sharing)によるクロスドメイン通信の傾向と対策 http://dev.classmethod.jp/cloud/cors-cross-origin-resource-sharing-cross-domain/ ↑関連† JavaScript S3 Link: S3 JavaScript