Both JPMorgan Chase and Wells Fargo posted a 32% growth rate in active mobile users over the first quarter of 2012 today.

Both banks are seeing rapid growth in active mobile banking users, and more measured growth in active online banking users, according to 1Q earnings reports released today.

(See here for what constitutes an “active user” at a bank.)

Chase counts over 32 million active online banking users, which is 5% growth over last year. Chase was very flat over most of 2012, posting little or no growth quarter over quarter, before posting a solid 4% growth figure for the first quarter of 2013.

Wells Fargo has smaller overall numbers for its online banking customers — 22 million — but a higher growth rate: 8% over last year. Interestingly, Wells has seen a rebound in growth rates in recent quarters that tracks closely with JPMorgan Chase’s growth. After a relatively stagnant period through most of 2012 with flat numbers, the bank posted a strong 5% growth number for the first quarter of 2013.

JPMorgan Chase’s banking portal, chase.com, is the most-visited banking portal in the US, according to the bank’s earning statement.

On the mobile side, Chase now boasts more than 13 million active users and has enjoyed 32% growth over last year and 7% growth over last quarter. The previous quarter, Chase saw 51% growth over the previous year and again, 7% growth over the previous quarter.

Chase’s mobile user base is 41% as large as its online user base, with likely a great deal of overlap. However, recent data-mining by comScore put a whopping two thirds of the bank’s mobile user base as “mobile-only.” If that strikes you as hard to believe, you’re not alone, but bear in mind that mobile-only users do occasionally visit the online channel.

Wells Fargo, with its smaller customer base, has seen similar growth numbers. The bank counts just over 10 million active mobile users, with 32% growth year over year, and 7% growth over last quarter. The previous quarter saw almost identical growth numbers. With 9.4 million active users, the bank clocked growth rates of 33% over last year and 6% over last quarter.

Wells’s mobile user base is 44% as large as its online user base. Both Wells Fargo and JPMorgan Chase, it should be noted, require mobile banking users to sign up online first, but given the numbers above, many users simply sign up online then move to being mobile-only users, or more precisely, active mobile users and inactive online users.

With the convergence of screens, epitomized by the tablet and Microsoft’s use of the same operating system for tablets and laptop/desktop systems, it is likely that the difference between the mobile and online experience will start to fade and, not so far off, disappear completely.

An account of both banks’ earnings is here.