Inverting Bits

by Mar 7, 2019

Occasionally it is necessary to invert the bits for a number. Most often, this is part of custom algorithms or checksum calculations. It raises the general question: what’s the easiest way to do this?

“Bit-Flipping” can be done with the -bnot operator like this:

$number = 76

$newnumber = -bnot $number

The result shows one caveat, though:


The operator always acts on signed 64-bit numbers. A better approach may be to use the -bxor operator and provide your own bit mask that you want to flip. For a byte, the bit mask would be 0xFF, and for an Int32, it would be 0xFFFFFFFF. Here is an example to flip the bits for a byte. We padded the string representation to 8 characters to make leading zeroes visible:

$number = 76
[Convert]::ToString([byte]$number,2).PadLeft(8, '0')

$newnumber = $number -bxor 0xFF
[Convert]::ToString($newnumber,2).PadLeft(8, '0')

The result matches:


Your learning points:

  • PowerShell comes with a rich set of binary operators that all start with -b…
  • To invert (flip) bits, you can use -bnot. To flip only some bits, use -bxor with your bit mask – PowerShell Conference EU 2019 – June 4-7, Hannover Germany – visit There aren’t too many trainings around for experienced PowerShell scripters where you really still learn something new. But there’s one place you don’t want to miss: PowerShell Conference EU – with 40 renown international speakers including PowerShell team members and MVPs, plus 350 professional and creative PowerShell scripters. Registration is open at, and the full 3-track 4-days agenda becomes available soon. Once a year it’s just a smart move to come together, update know-how, learn about security and mitigations, and bring home fresh ideas and authoritative guidance. We’d sure love to see and hear from you!

Twitter This Tip! ReTweet this Tip!