How to Decode Base64 in Excel (2 Suitable Examples)

Method 1 – Apply an Excel VBA Code for a HTML Decode String

Steps:

Go to the Developer tab from the ribbon.
Click on Visual Basic from the Code category to open the Visual Basic Editor. Or, press Alt + F11.

Click on Module from the Insert drop-down menu bar.

This will create a Module in your workbook.
Copy and paste the VBA code shown below into the module.

VBA Code:

Public Function HtmlDecode(StringToDecode As Variant) As String
    Set HFile = CreateObject("htmlfile")
    Set a = HFile.createElement("T")
    a.innerHTML = StringToDecode
    HtmlDecode = a.innerText
End Function

Press Ctrl + S to save the file.

Go back to the sample Excel sheet.
Insert the following formula into the result. Use your own cell reference for the source if you’re making a table from scratch.

=HtmlDecode(B5)

Press the Enter key.

Drag the Fill Handle icon down to duplicate the formula over the range or double-click on the plus (+) symbol.

You will see the results.

Read More: How to Change Encoding in Excel

Method 2 – Create a User Defined Function in Excel to Decode Base64

Steps:

Open a VBA Module (see Method 1 for instructions if needed).
Copy and paste the following VBA code into the module.

VBA Code:

Function Decoding(b64$)
    Dim i
    With CreateObject("Microsoft.XMLDOM").createElement("b64")
        .DataType = "bin.base64": .Text = b64
        i = .nodeTypedValue
        With CreateObject("ADODB.Stream")
            .Open: .Type = 1: .Write i: .Position = 0: .Type = 2: .Charset = "utf-8"
            Decoding = .ReadText
            .Close
        End With
    End With
End Function

Hit Ctrl + S.

Return to the Excel sheet now.
Put the following formula into the result cell, where the reference in the formula is the cell with the text you wish to decode:

=Decoding(B5)

Hit the Enter key.

NOTE: At the conclusion of a Base64 function, the equals sign (=) denotes padding. This is because the size of 8-bit strings and Base64 strings don’t match.

To copy the formula over the range, drag the Fill Handle symbol downward. Alternatively, double-click the plus (+) sign to AutoFill the range.

You can see the results.

How to Encode Base64 in Excel

Steps:

Access the Visual Basic Editor by pressing Alt + F11.
Pick the Module from the drop-down box under Insert.
Copy this code in the module.

VBA Code:

Function Encoding(text$)
    Dim i
    With CreateObject("ADODB.Stream")
        .Open: .Type = 2: .Charset = "utf-8"
        .WriteText text: .Position = 0: .Type = 1: i = .Read
        With CreateObject("Microsoft.XMLDOM").createElement("b64")
            .DataType = "bin.base64": .nodeTypedValue = i
            Encoding = Replace(Mid(.text, 5), vbLf, "")
        End With
        .Close
    End With
End Function