Just copy/paste your text into the text box as illustrated here below and click on the Process button. The base64_encoded text will be decoded or the ASCII text will be base64 encoded. The Process ...

My base 64 encoded test case string is located in the file base64_data. The hash of the base 64 encoded input (and the expected hash result after the decode/encode) is e506287b79051b4fa3fba38a2bc70e90 ...