Credit unions are having a tough time keeping up with some of the benefits offered by online savings accounts, according to a new study by GoBankingRates.com, a personal finance website that claims more than 2 million unique impressions each month.

The study noted that online savings accounts and certificates of deposit (CDs) offer significantly higher yields and require lower minimum deposits, on average, than banks and credit unions offering traditional, offline accounts, the study said.

Online savings account rates are 618 percent higher and online CDs are 58 percent higher than traditional versions of the same products, according to the study. However, conventional checking and money market accounts offer equal or higher yields and lower minimum deposits than online versions of the accounts, on average, said GoBankingRates.

To compete with online savings options, the company said, a growing number of traditional, brick-and-mortar banks and credit unions now provide online-only accounts in addition to their conventional options — but with the option to visit a branch. 

Here are other key findings from the study:

• Average minimum deposit requirements for online savings accounts are 55 percent less than that of traditional savings accounts.

• Average minimum deposit requirements for online CDs are 50 percent less than that of traditional CDs.

• Checking account yields are the same across online and traditional banking options and only vary slightly ($154) in terms of minimum deposit required.

The study, comparing online and traditional minimum deposit requirements and interest rates on savings, checking, money market and CD accounts, was compiled using the GoBankingRates.com database, which is powered by Informa Research Services, Inc., and aggregates interest rates from more than 4,000 local, national and online financial institutions, the company said.

Last month, the company, owned by ConsumerTrack Inc., launched a new product, GoBankingRates Local, designed to help credit unions and other financial institutions entice new account holders through locally targeted personal finance content and interest rate data.