Vanguard launched the first index mutual fund in 1976. Over the years, they have expanded into exchange-traded funds (ETF) and target-date funds, all while keeping fees around their funds low.
Blackrock also played an essential role in helping to navigate the financial crisis by working with other firms to value mortgage-backed securities properly.
Vanguard has a unique ownership structure where the clients own the company, and no outside owners seek to profit from the company’s investments.
From the comparison above, you see there aren’t significant differences between similar Vanguard and Blackrock funds.
Your decision on where to invest your money may come down to other factors such as the convenience of their platform or other services on how you use either company.