ブラウザでBase64エンコードされた画像をデコードして閲覧する

(Chrome, Safari, Firefoxで確認)

ブラウザのアドレスバーにdata:image/jpeg;base64,{{Base64文字列}}みたいな感じで入力して移動すると表示できます。

とりあえずGooglefaviconで。下のリンクをクリックするか、テキストをトリプルクリックなんかでコピーしてアドレスバーに貼り付けて移動してみてください。画像が表示されるのが確認できると思います。

リンク形式

リンク

テキスト形式

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

MIMEタイプのところを変えればPNGやGIFといった他の形式の画像や、テキストファイルなんかも表示できそうですね。下は「Base64テスト」と書かれたテキストファイルをBase64エンコードした例です(もし文字化けしていればブラウザのエンコード指定をUTF-8に変更すれば正しく表示されると思います)。

リンク

data:text/plain;base64,QmFzZTY044OG44K544OICg==

Google画像検索結果のimgのsrc属性に使われているのを見て知りました:)

追記

こういうのはData URI schemeというらしい。