In computing, bit twiddler may refer to:

• A piece of source code that does bit twiddling, which may mean:
  • Doing bit manipulation;
  • Interacting with computer hardware, especially when using a bit-banging technique;
  • Reading or writing binary file formats; or
  • Being unnecessarily complex, perhaps due to premature optimization
• A programmer who writes bit twiddlers, as described above
• A hacker, an enthusiast or a programmer with profound understanding of the fundamentals of computer operation
• A hex editor, a software application that allows the manipulation of binary computer files