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.

What is the ANSI Escape Codes?

Searchable ANSI/VT100 escape sequence reference covering CSI cursor moves, erase commands, SGR text modes, screen buffer and OSC sequences, with copyable literal bytes and examples. It runs free in your browser on Gera Tools, with nothing uploaded.

ANSI Escape Codes — Gera Tools

Name: ANSI Escape Codes
Creator: Gera Tools
License: https://creativecommons.org/licenses/by/4.0/

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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 (decimal 27, hex 0x1B, written \e or \033 in most languages). This reference groups the common sequences by purpose and lets you copy each one with the real ESC byte already in place.

The four sequence families

CSI — Control Sequence Introducer (`ESC [`)

The workhorse of terminal control. Every CSI sequence is ESC [ followed by optional numeric parameters separated by semicolons, then a terminating letter:

Sequence	Action	Example
`ESC[{n}A`	Move cursor up n rows	`ESC[3A` — up 3
`ESC[{n}B`	Move cursor down n rows	`ESC[1B` — down 1
`ESC[{n}C`	Move cursor forward n columns	`ESC[5C`
`ESC[{n}D`	Move cursor back n columns	`ESC[2D`
`ESC[{row};{col}H`	Move cursor to absolute position	`ESC[1;1H` — top-left
`ESC[2J`	Erase entire screen	(clears display)
`ESC[K`	Erase to end of line	(clear rest of current line)
`ESC[0m`	Reset all SGR attributes	Always end colored output with this
`ESC[1m`	Bold / bright
`ESC[4m`	Underline
`ESC[38;5;{n}m`	Set foreground to 256-color code n
`ESC[48;5;{n}m`	Set background to 256-color code n
`ESC[38;2;{r};{g};{b}m`	Set foreground to 24-bit RGB	True-color terminals only

SGR — Select Graphic Rendition

SGR sequences (ESC[...m) change text appearance. Multiple attributes can be combined with semicolons: ESC[1;4;31m sets bold, underline, and red foreground simultaneously. Always reset with ESC[0m to avoid leaking attributes into subsequent output.

OSC — Operating System Command (`ESC ]`)

OSC sequences are for communication with the terminal emulator itself rather than the text display:

OSC 0 / OSC 2: set the window title — ESC]2;My Title\a
OSC 8: hyperlinks — ESC]8;;https://example.com\aclick here\ESC]8;;\a renders a clickable link in supporting terminals (iTerm2, Kitty, recent GNOME Terminal versions).

OSC sequences end with BEL (\a, 0x07) or a string terminator (ESC \).

DEC private sequences

Prefix ESC[? for DEC private modes. The two most common:

ESC[?25l / ESC[?25h — hide / show cursor (useful for TUI apps)
ESC[?1049h / ESC[?1049l — enter / exit the alternate screen buffer

How it works

When you copy a sequence from this reference, the \e placeholder is replaced with the actual ESC byte (0x1B). The numeric placeholders {n}, {row}, {col} are values you substitute; omitting a number usually defaults it to 1.

Practical examples

# Clear screen and home cursor
printf '\e[2J\e[H'

# Print bold red text then reset
printf '\e[1;31mError:\e[0m something went wrong\n'

# Move cursor to row 5, col 10
printf '\e[5;10H'

# Hide cursor during a progress bar, restore after
printf '\e[?25l'
# ... your progress output ...
printf '\e[?25h'

In bash, ANSI-C quoting ($'\e[...') or printf with \033 both work reliably across shells. Avoid using raw echo -e in scripts, as its behaviour varies between systems.