Utilities for working with binary data and bit manipulation in Dart.

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NOTE: Unless otherwise noted, all functionality is based around treating bits as little endian, that is in a 32-bit integer the leftmost bit is 31 and the rightmost bit is 0


This library supports an Integral data type for fluent bit manipulation:

print(uint8.toBinaryPadded(196)); // '11000100'

Because of Dart's ability to do advanced inlining in both the Dart VM and dart2js, this library should perform well and be extremely easy to use for most use cases. For example, it's used in an arm7_tdmi emulator.


This library has a combination of top-level methods, and instance methods of pre-defined Integral data types (see below). For example there are two ways to clear (set to 0) a bit:

// Sets the 0th bit in an (int) bits to 0
bits = clearBit(bits, 0)

However, this will not do range validation. Use Integral#clearBit:

// Sets the 0th bit in a uint32 to 0.
// In dev-mode, if either bits or `n` is out of range it throws.
bits = uint32.clearBit(bits, 0);

Integral data types

  • bit
  • int4
  • int8
  • int16
  • int32
  • int64
  • int128
  • uint4
  • uint8
  • uint16
  • uint32
  • uint64
  • uint128

Learning more

See the dartdocs for more about the API.