Hex dump

In computing, a hex dump is a hexadecimal view (on screen or paper) of computer data, from RAM or from a file or storage device. Looking at a hex dump of data is commonly done as a part of debugging, or of reverse engineering.

In a hex dump, each byte (8-bits) is represented as a two-digit hexadecimal number. Hex dumps are commonly organized into rows of 8 or 16 bytes, sometimes separated by whitespaces. Some hex dumps have the hexadecimal memory address at the beginning and/or a checksum byte at the end of each line.

Although the name implies the use of base-16 output, some hex dumping software may have options for base-8 (octal) or base-10 (decimal) output. Some common names for this program function are hexdump, od, xxd and simply dump or even D.

A sample partial hex dump of a program, as produced by the Unix program hexdump:

The above example, however, represents an ambiguous form of hex dump, as the byte order may be uncertain. Such hex dumps are good only in the context of a well-known byte order standard or when values are intentionally given in their full form (and may result in variable number of bytes), such as:

When explicit byte sequence is required (for example for hex dump of machine code programs or ROM content) a byte-by-byte representation is favoured, commonly organized in 16-byte rows with an optional divider between 8-byte groups:

Rarely a condensed form is also used, without whitespaces between values:

A Unix default display of those same bytes as two-byte words on a modern x86 (little-endian) computer would usually look like this:

Often an additional column shows the corresponding ASCII text translation (e.g. hexdump -C or hd):

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