Colored Logger

A simple yet powerful colored logging utility for Dart and Flutter applications that enhances console output with ANSI colors and styles.

pub package

Screenshot

Features

  • Color-coded log levels: Info (blue), success (green), warning (yellow), error (red)
  • Rich text formatting: Bold, italic, underline, strikethrough, and more
  • Extensive color support: Basic colors, bright colors, 256-color palette, and true RGB colors
  • Fluent API: Chain multiple styles together with a clean, readable syntax
  • String extensions: Apply styles directly to strings with extension methods

Installation

dependencies:
  colored_logger: ^2.1.0

See Ansi Support for more details about ansi support.

Basic Usage

import 'package:colored_logger/colored_logger.dart';

void main() {
  // Basic log levels
  ColoredLogger.info('Server started on port 8080');
  ColoredLogger.success('Operation completed successfully');
  ColoredLogger.warning('This is a warning message');
  ColoredLogger.error('An error occurred');

  // Custom styling
  ColoredLogger.colorize(
    'Custom message with bold and cyan text',
    styles: [Ansi.bold, Ansi.cyan],
    prefix: '[STYLED] ',
  );
}

String Extensions

import 'package:colored_logger/colored_logger.dart';

void main() {
  // Apply styles directly to strings
  print('Bold text'.bold());
  print('Red text'.red());

  // Chain multiple styles
  print('Bold italic green text'.bold.italic.green());

  // Advanced colors
  print('256-color text'.fg256(201)());
  print('RGB color text'.fgRgb(255, 100, 0)());

  // Special effects
  print('Rainbow text'.rainbow());
}

Ansi Class

import 'package:colored_logger/colored_logger.dart';

void main() {
  // Static methods
  print(Ansi.bold.paint('Bold text'));
  print(Ansi.red.paint('Red text'));

  // Combine styles
  final boldRed = Ansi.bold.combine(Ansi.red);
  print(boldRed.paint('Bold red text'));

  // Using + operator
  final boldItalicGreen = Ansi.bold + Ansi.italic + Ansi.green;
  print(boldItalicGreen.paint('Bold italic green text'));

  // Fluent chaining API
  final customStyle = Ansi.empty.cBold.cItalic.cRed.cBgYellow;
  print(customStyle.paint('Custom styled text'));
}

Available Styles

Text Formatting

  • bold, faint, italic, underline, doubleUnderline
  • strikethrough, overline, inverse, conceal
  • slowBlink, fastBlink, superscript, subscript
  • framed, encircled

Colors

  • Standard: black, red, green, yellow, blue, magenta, cyan, white
  • Bright: brightBlack, brightRed, brightGreen, brightYellow, brightBlue, brightMagenta, brightCyan, brightWhite
  • Background: bgBlack, bgRed, bgGreen, bgYellow, bgBlue, bgMagenta, bgCyan, bgWhite
  • Bright Background: bgBrightBlack, bgBrightRed, bgBrightGreen, bgBrightYellow, bgBrightBlue, bgBrightMagenta, bgBrightCyan, bgBrightWhite

Extended Colors

  • 256-color: fg256(index), bg256(index)
  • RGB: fgRgb(r, g, b), bgRgb(r, g, b)

ANSI Support

ANSI escape codes might not render if your terminal lacks support or if isSupportAnsi returns false.

  • Use paint() or call() on StyledString to force ANSI rendering, even if isSupportAnsi is false. e.g:

    • print('Text'.bold.paint())
    • print('Text'.bold())

  • Otherwise, print('Hello'.red) may not colorize the text because not all recognized terminals can report whether they support ANSI escape sequences.

Force ANSI support with environment variables:

# Dart
dart run --define=ANSI=true main.dart

# Flutter
flutter run --dart-define=ANSI=true

To check you have ANSI support in your terminal with showAnsiInfo() function.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Libraries

colored_logger