constructs a ByteArray object containing the byte values bi.


constructs a ByteArray object by extracting byte values from a Base64-encoded string.


  • ByteArray stores data in a memory-efficient way, with the total number of bytes used being close to the length of the array.
  • When displayed in InputForm, a ByteArray object displays as ByteArray["string"], where "string" encodes the bytes in Base64 encoding.
  • In ByteArray[{b1,b2,}], all the byte values bi should be integers between 0 and 255.
  • ByteArray[{}] and ByteArray[""] produce empty byte arrays. »
  • StringToByteArray[ByteArray[]] yields a string by interpreting the contents of a byte array using UTF-8 encoding.
  • ExportByteArray[expr,"fmt"] exports an expression via the export format "fmt", giving the result as a byte array. ImportByteArray can be used to convert a byte array to an expression.
  • Normal[ByteArray[]] yields the list of byte values in the byte array.
  • Functions such as Length and Equal work with ByteArray objects.
  • Functions such as First, Last, Min, and Max yield integer byte values.
  • Part works on ByteArray objects, yielding an integer byte value when it returns a single element, and a ByteArray object when it returns multiple elements.


open allclose all

Basic Examples  (2)

Create a ByteArray from a list of byte values:

Convert back to a list of byte values:

Create a ByteArray from a Base64-encoded string:

Convert to a list of byte values:

ByteArray uses Base64 in InputForm:

Scope  (6)

Get the length of a ByteArray:

Extract parts of a ByteArray:

Extract a sequence of bytes:

Convert to an ordinary array:

Reverse a byte array:

Read in a "WXF" file as a ByteArray:

Read it in 30 bytes at a time:

Close the incrementally read file:

Export an image as a ByteArray:

Interpret a ByteArray as a PNG image:

Properties & Relations  (6)

ByteArray uses Base64 encoding of its data in InputForm:

This string can be generated using BaseEncode:

Convert a byte array to an ordinary, one-dimensional list using Normal:

Compute the length of a byte array:

Create empty byte arrays:

Convert a ByteArray to a string using ByteArrayToString:

Convert back to a ByteArray using StringToByteArray:

BinarySerialize converts expressions to a sequence of bytes returned as a ByteArray:

It can be reversed using BinaryDeserialize:

Wolfram Research (2015), ByteArray, Wolfram Language function, (updated 2023).


Wolfram Research (2015), ByteArray, Wolfram Language function, (updated 2023).


Wolfram Language. 2015. "ByteArray." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2023.


Wolfram Language. (2015). ByteArray. Wolfram Language & System Documentation Center. Retrieved from


@misc{reference.wolfram_2024_bytearray, author="Wolfram Research", title="{ByteArray}", year="2023", howpublished="\url{}", note=[Accessed: 17-June-2024 ]}


@online{reference.wolfram_2024_bytearray, organization={Wolfram Research}, title={ByteArray}, year={2023}, url={}, note=[Accessed: 17-June-2024 ]}