Problem with Base64 conversion and Excel files

gtrennert2

Hello,

I have an application that gets Excel files encoded in Base64
I try to decode the Base64, put the obtained text into a blob to download it later with DownloadFromStream
But I get corrupted Excelfiles
I developped a little procedure (see link) to see if Base64-coding and Base64-decoding is altering the data.

The result of the procedure is :
Text File identical : True
Excel File identical : False
I tested the Base64 texts with https://base64.guru/converter/ and there seems to be no problem
Has somebody a hint to see where the problem comes from ?

vaprog

Where is the difference? Is it only the padding at the end of the encoded string?

I assume you have tried encoding an xlsx file yourself and decoding it again. Does this also corrupt the file?

Have you checked which Base64 standard each of your strings adhere to?