ANSI Bold Text - Escape Code 1 for Bold Terminal Output

Bold Text with ANSI Code 1

Bold (also called "increased intensity") is the most commonly used ANSI text formatting attribute. It is activated with SGR code 1 and reset with code 22 (or the general reset code 0).

Basic Usage

# Bash
echo -e "\033[1mThis text is bold\033[0m"

# Python
print("\033[1mThis text is bold\033[0m")

# Node.js
console.log("\x1b[1mThis text is bold\x1b[0m");

# Go
fmt.Println("\033[1mThis text is bold\033[0m")

# C
printf("\033[1mThis text is bold\033[0m\n");

Bold + Color

Bold combined with color creates high-impact text:

# Bold red (error messages)
echo -e "\033[1;31mERROR: Something went wrong\033[0m"

# Bold green (success messages)
echo -e "\033[1;32mSUCCESS: Operation completed\033[0m"

# Bold yellow (warnings)
echo -e "\033[1;33mWARNING: Deprecated function\033[0m"

# Bold cyan (info messages)
echo -e "\033[1;36mINFO: Processing started\033[0m"

Bold vs Bright Colors

Historically, some terminals rendered "bold" text by using the bright variant of the current color rather than increasing font weight. This is why codes 1;30 through 1;37 sometimes look identical to codes 90 through 97. Modern terminals typically apply actual bold rendering (increased font weight) in addition to the color.

Resetting Bold Only

To reset bold without affecting other styles, use code 22:

echo -e "\033[1;31mBold red \033[22mnormal red\033[0m"

Code 22 resets both bold (1) and dim (2) to normal intensity, while preserving other attributes like color and underline.

Terminal Compatibility

Bold is universally supported across all terminal emulators. However, the visual rendering depends on the terminal font — some fonts have distinct bold weights while others may simply render bold text in a brighter color.