Objective-C Luhn Algorithm

Luhn Credit Card Checker Algorithm

View the Project on GitHub MaxKramer/ObjectiveLuhn

Luhn Algorithm

Build Status

This is just a quick port of the Luhn Algorithm, generally used for validating Credit Card details, to Objective-C (iOS).

I have included an example project showing how the class works. It's as simple as calling a single method. No special formatting required, it's all done within the class.

In order to use the example project, you must run pod install before opening the workspace.


Import the header:

#import "Luhn.h"

Call the class method returning a BOOL as to whether the string is valid or not:

BOOL isValid = [Luhn validateString:@"some credit card number"];

if (isValid) {
    // process payment   
else {
    // alert user

Alternatively, you can use the NSString category (no additional imports required):

NSString *ccNumber = @"378282246310005";
BOOL isValid = [ccNumber isValidCreditCardNumber];

You can also get the type of the credit card i.e. Visa, Diners, Amex, etc:

OLCreditCardType = [ccNumber creditCardType];
// or
OLCreditCardType = [Luhn typeFromString:ccNumber];

If you come across any issues or have a feature request, please open an issue or find me on:

Twitter: @maxkramer

Website: http://maxkramer.co


Name Website Reason
Paypal http://www.paypalobjects.com/en_US/vhelp/paypalmanager_help/credit_card_numbers.htm List of valid credit card numbers for the unit tests


Ayaka Nonaka for updating the Cocoapod spec and helping me with other aspects of the project!

Twitter: @ayanonagon


This project is licensed under the MIT license.