John’s Base64 Encoder / Decoder

I recently found myself doing some web development where two systems talked to each other over SOAP. XML documents were being passed back and forth and were encoded with Base64. To make sure everything was working I had to be able to encode and decode these Base64 strings so I knocked up a little application that I could copy and paste text into and convert back and forth from Base64 to English. It looks like this:

John's Base64 Encoder / Decoder

Since I found it useful (and will no doubt use it again in the future) I thought I’d put it up here in case anybody else finds they need a tool to do the same thing. It runs on Windows only (all versions from Windows 98 upwards) and requires that you’ve installed the Microsoft .NET Framework 2.0 first – which you can download here.

As it’s a developer’s tool I’ve not bothered putting an installer together. To run it simply download the following ZIP file and copy the executable (along with the readme file if you wish) into a place of your choosing and run it:

(Version 1.0 – 180KB)

Hopefully you’ll find it useful!

14 Comments Join the Conversation

  1. Hey!

    Finally a working b64 enc/dec application which is not a virus…
    Thanks dude 😉



  2. I use base64 to send otherwise non-sendable stuff to satellites.
    This IEEE-754 to base64 and back is a royal pain (sorry Mom…).

    I’m glad you’ve got it working and I’m sorry I never published mine long ago. Apologies. I’ll look into getting stuff uploaded following your example.

    Stay well!


  3. Nice work, John. But did you know the program certutil.exe, included in Windows 7, will decode and encode files to/from Base64? It does a lot of other things too. Just type certutil -? from a command line and you’ll see what it does. Nonetheless, your utility is more convenient most of the time. But if you need to convert a large file, the CertUtil may be a better option.


  4. Hi John,
    I have an string looks like base64. But I cannot decode it. Can you show me what I wrong?



    • It is working, it’s just that the text being decoded is either garbage, or included characters that the various decoders out there can’t decode appropriately. So unfortunately, no, I can’t help!


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