Node.js ANSI Colors - Console.log with Color Codes

Colored Console Output in Node.js

Node.js uses \x1b as the escape character for ANSI sequences. This guide covers both native and library-based approaches.

Raw ANSI Sequences

// Basic colors
console.log("\x1b[31mRed text\x1b[0m");
console.log("\x1b[1;32mBold green\x1b[0m");

// 256 colors
console.log("\x1b[38;5;208mOrange\x1b[0m");

// True color
console.log("\x1b[38;2;255;165;0mTrue orange\x1b[0m");

Color Utility Module

const colors = {
  reset: "\x1b[0m",
  bold: "\x1b[1m",
  dim: "\x1b[2m",
  red: "\x1b[31m",
  green: "\x1b[32m",
  yellow: "\x1b[33m",
  blue: "\x1b[34m",
  magenta: "\x1b[35m",
  cyan: "\x1b[36m",
  white: "\x1b[37m",
  bgRed: "\x1b[41m",
  bgGreen: "\x1b[42m",
};

const colorize = (text, color) =>
  `${colors[color]}${text}${colors.reset}`;

// Usage
console.log(colorize("Error!", "red"));
console.log(colorize("Success!", "green"));

Tagged Template Literal

function ansi(strings, ...values) {
  const codes = { r: 31, g: 32, y: 33, b: 34, m: 35, c: 36 };
  return strings.reduce((result, str, i) => {
    const val = values[i] !== undefined ? values[i] : "";
    return result + str + val;
  }, "");
}

console.log(`\x1b[31mRed \x1b[32mGreen \x1b[0m`);

Detecting Color Support

const supportsColor = process.stdout.isTTY
  && !process.env.NO_COLOR
  && process.env.TERM !== "dumb";

function maybeColor(text, code) {
  if (supportsColor) {
    return `\x1b[${code}m${text}\x1b[0m`;
  }
  return text;
}

Using with Streams

// Write directly to stdout for more control
process.stdout.write("\x1b[33mProcessing... \x1b[0m");
// ... do work ...
process.stdout.write("\x1b[32mdone\x1b[0m\n");

ESM and TypeScript

// color.ts
export const ANSI = {
  red: (s: string) => `\x1b[31m${s}\x1b[0m`,
  green: (s: string) => `\x1b[32m${s}\x1b[0m`,
  bold: (s: string) => `\x1b[1m${s}\x1b[0m`,
  rgb: (r: number, g: number, b: number, s: string) =>
    `\x1b[38;2;${r};${g};${b}m${s}\x1b[0m`,
} as const;

console.log(ANSI.red("Error"));
console.log(ANSI.rgb(255, 165, 0, "Orange"));