Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I want to insert a null character (ASCII Value 00) into an open file in Notepad. A program that is reading this file is expecting 00 at the end, but it's getting the ASCII value for space - 20.

How can I achieve this?

share|improve this question

migrated from Oct 28 '09 at 0:11

This question came from our site for professional and enthusiast programmers.

I had hoped that holding Alt and pressing four zero on the numpad would insert the null the same way it inserts all of the fÜn printable characters but it doesn't. – tkryger Oct 26 '09 at 7:06

Alt + 256 works for me. But thats just one at a time.

The plugin HEX-editor is easier if you want heaps of Nul's at a time.

share|improve this answer
wait, im talking about Notepad++ – RND Jan 27 '10 at 3:55
Thanks for you answer! – Konstantin Spirin Feb 18 '10 at 2:37
Excellent, that's what I needed. – noob Jan 23 '13 at 9:06

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=
share|improve this answer

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.

share|improve this answer

try new a file called a.txt, then open it with hex editor like ultraEdit, ctrl + H to enter hex editing mode, at that time, you will be fine with whatever byte you wanna insert.

share|improve this answer

notepad++ :

  1. TYPE 00 00
  2. Go to Plugins > Converter & Click on "HEX to ASCII"
share|improve this answer
Welcome to Super User! Thanks for trying to help. Unfortunately, a previous answer (from alex2k8) already includes this information. If you have more to add, please edit your answer. – Ben N Jan 9 at 1:57
This duplicates another answer and adds no new content. Please don't post an answer unless you actually have something new to contribute. – DavidPostill Jan 9 at 20:16
Sorry. I will think twice the next time. – Idontreallywolf Jan 13 at 8:37

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.