What is the ESC character in an ANSI sequence?

ESC is the escape control character, decimal 27 or hex 0x1B. Most ANSI sequences start with ESC followed by '[' to form a Control Sequence Introducer (CSI). In code it is often written as \e, \033 or \x1b.

What is the difference between CSI and OSC sequences?

CSI sequences begin with ESC [ and control cursor movement, erasing and text attributes. OSC (Operating System Command) sequences begin with ESC ] and handle things like the window title and hyperlinks, terminated by BEL or a string terminator.

How do I clear the terminal screen with ANSI?

Send ESC[2J to erase the whole screen, often combined with ESC[H to move the cursor to the top-left. Many tools also send ESC[3J to clear the scrollback buffer.

Why does {n} appear in some sequences?

{n} is a numeric parameter you provide. For example ESC[5A moves the cursor up 5 rows. If you omit the number, most terminals default it to 1.

How do I use these sequences in a shell script?

Use printf with an escape, for example printf '\033[2J' to clear the screen, or bash ANSI-C quoting like $'\e[1m' for bold. The Copy button already inserts the real ESC byte for you.

ANSI Escape Codes — Gera Tools

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Control the terminal with escape sequences

ANSI (also called VT100) escape sequences are short byte strings that tell a terminal to move the cursor, clear regions, change text style, switch screen buffers, or set the window title. They all start with the ESC control character. This reference groups the common sequences by purpose and lets you copy each one with the real ESC byte already in place.

How it works

Almost every sequence here is a Control Sequence Introducer: the bytes ESC [ followed by optional numeric parameters and a final letter that selects the action. For example ESC[{row};{col}H positions the cursor, where {row} and {col} are 1-based numbers you supply. SGR (Select Graphic Rendition) sequences like ESC[1m (bold) and ESC[0m (reset) change text appearance. OSC sequences begin with ESC ] and handle window titles and hyperlinks. When you copy, the \e placeholder is replaced with the actual ESC byte (0x1B).

Tips and examples

Clear the screen and home the cursor with ESC[2J then ESC[H.
Wrap colored output in ESC[0m at the end so later text is not stained.
In bash use ANSI-C quoting: printf '\e[1mBold\e[0m\n'.
{n} and {row};{col} are parameters you fill in; omitting a number usually defaults it to 1.
OSC 8 hyperlinks let you embed clickable links in supporting terminals without showing the raw URL.