From @ThomasHabets on October 10, 2014 8:7

Original issue 327 created by charly.rohart on 2013-09-26T14:25:45.000Z:

Can you add support for 8 Digits OTP codes?

6 digits is the most common use Ok - but 8 is frequently preferred when strong security is required.
The OATH internal code is the same in both - just a minor adjustment is required to support 8 digits.
Is is planned in a near future in the roadmap?

Copied from original issue: google/google-authenticator#326