Emails Validator

Fast and strict email validator for Dart and Flutter.

The validator uses a low-allocation parser (no regular expressions), keeps legacy-compatible behavior by default, and now also supports detailed error codes and configurable validation profiles.

Features

  • High-performance parser (codeUnitAt, early exits, no split in hot path)
  • Backward-compatible default validation behavior
  • Detailed validation result with exact failure reason
  • Custom validation options (standard and relaxed profiles)
  • Batch APIs for map/list validation with custom options
  • Optional debug logs (debugEnabled, disabled by default)

Installation

dependencies:
  emails_validator: ^1.1.0

dart pub get

Quick start

import 'package:emails_validator/emails_validator.dart';

void main() {
  final isValid = EmailsValidator.validate('user@example.com');
  print(isValid); // true
}

Detailed validation

final result = EmailsValidator.validateDetailed('  User.Name+tag@EXAMPLE.COM  ');

print(result.isValid);          // true
print(result.normalizedEmail);  // User.Name+tag@example.com
print(result.error);            // null

For invalid input:

final result = EmailsValidator.validateDetailed('user@@example.com');
print(result.isValid); // false
print(result.error);   // EmailValidationError.multipleAtSymbols
print(result.message); // More than one @ symbol found

Validation options

// Backward-compatible defaults.
final standard = EmailsValidator.validate('user@localhost'); // false

// Relaxed profile for internal tooling.
final relaxed = EmailsValidator.validateWithOptions(
  'user@localhost',
  options: EmailValidationOptions.relaxed,
); // true

// Custom profile.
final custom = EmailValidationOptions.standard.copyWith(
  allowQuotedLocalPart: false,
);
final ok = EmailsValidator.validateWithOptions(
  '"john doe"@example.com',
  options: custom,
); // false

Batch APIs

final emails = [
  'user@example.com',
  'invalid-email',
  'user@localhost',
];

final results = EmailsValidator.validateList(emails);
// {'user@example.com': true, 'invalid-email': false, 'user@localhost': false}

final relaxedResults = EmailsValidator.validateListWithOptions(
  emails,
  options: EmailValidationOptions.relaxed,
);
// {'user@example.com': true, 'invalid-email': false, 'user@localhost': true}

final valid = EmailsValidator.getValidEmailsWithOptions(
  emails,
  options: EmailValidationOptions.relaxed,
);

Performance benchmark

Run:

dart run benchmark/benchmark.dart

Current local benchmark (March 3, 2026) shows ~3x+ speedup versus legacy implementation on both compatibility and extended datasets.

Debug logs

Debug logging is disabled by default:

EmailsValidator.debugEnabled = true;

Validation limits

  • Total length: 5..254
  • Local part: up to 64 chars
  • Domain: up to 253 chars
  • Domain label: up to 63 chars
  • Standard profile requires at least two domain labels (example.com)

Testing

dart test

License

MIT

Libraries

emails_validator