Hex Dump Calculator

How it is calculated

The text is treated as raw bytes (UTF-8, as the browser sends it) and cut into rows of 16. Each row is OFFSET HH HH ... HH |ASCII|. The offset is the position of the row's first byte, written as 8 hexadecimal digits starting at 00000000 and growing by 16 (hex 10) per row. Then come the 16 bytes as two-digit upper-case hex values, and a gutter between vertical bars where a byte from 0x20 to 0x7E is shown as its character and every other byte (control codes, newlines, and each byte of a multi-byte character) as a dot. A short last row is padded with blanks so the gutters line up.

Besides the dump the tool reports the number of bytes and of rows, with the unit word in the page language. The count is of bytes, not characters, so one accented letter such as é takes 2 bytes. Empty input gives no result.

Common mistakes

• Counting characters instead of bytes: the text Café has 4 characters but 5 bytes, because é is stored as C3 A9 and appears as two dots in the gutter.
• Reading a dot in the gutter as a real full stop. It also stands for newlines, tabs and any byte outside printable ASCII, so check the hex column to tell them apart (0A is a line feed, 09 a tab, 2E a real full stop).
• Reading the offset as decimal. Row offsets are hexadecimal, so the second row starts at 00000010, which is byte 16, and the third at 00000020, which is byte 32.
• Expecting a file dump. The tool shows exactly the text you type or paste, so line endings may differ from a saved file (a line break can appear as 0A or as 0D 0A depending on how it reached the tool).
• Comparing with a tool that prints lower-case hex or groups bytes in pairs. The values are the same, but this layout is upper-case with a space between single bytes.