How to Insert a Null Character (ASCII 00) in Notepad?

With Notepad++

1. Go to Edit > Character Panel to show the ASCII Insertion Panel.

2. Put the cursor where you want to insert the character.

3. Double-click the character (in the Character column) to insert.

   

With Notepad++

From HEX

1. Type 00 00 00
2. Select this text
3. TextFX > TextFX Convert > Convert Hex to text

From Base64

1. Type AA==
2. Select this text
3. Plugins > MIME Tools > Base64 Decode

The mapping is:

NUL -> AA=
NUL NUL -> AAA=
NUL NUL NUL -> AAAA

Normal text editors such as Notepad usually do not have the capability to enter NUL characters into files. What you probably want to do is to use a "hex editor" (some text editors also have a "hex" mode). This will let you enter NUL characters, or any other byte you might need.