The main Okteta window has the following components: a menu bar, a toolbar, a status bar, one or several sidebars with tools, and the main view with the tabbed data views.

When a file is opened or a new byte array is created, the bytes contained are listed consecutively in lines with a given number of bytes per line. They are displayed in two variants: as the numeric values of the bytes and as the characters assigned to the values. Values and characters can be shown either separated in two columns or next to each other with the value on top of the character. On the left side the offsets of the first byte in each line are shown.

The handling is similar to that of most text editors: the data can be edited, cut, copied, pasted, dragged and dropped much as text in these can. A cursor marks the current position. Pressing the Insert key toggles between the overwrite and insert modes. The overwrite mode is stricter than in text editors, as it doesn't allow any operation which changes the size of the byte array.

Other than in text editors the content is displayed in two variants. Only one of these is active with regard to new input. There are two linked cursors shown for the value and the character display, the cursor of the active one is blinking. With the characters active, characters can be entered as known from text editors. With the values active, typing a digit will open a minimal editor to enter the rest of the value.

The search dialog allows the user to search for a specific string of bytes, definable as values (hexadecimal, decimal, octal, binary) or text (current 8-bit encoding or UTF-8).

Multiple byte arrays can be open at the same time, but only one can be active. Use the Windows menu to select which byte array will be active.