Can't speak of quality/completeness: https://www.alphavantage.co/ https://jbmarwood.teachable.com/p/marwood-research
What's the premium pricing for AlphaVantage? Currently they seem to offer 5 API queries per minute for free. That's a joke I assume, same as offering someone a bicycle with one pedal.
Because of course everything in life should be free and that they only provide 5 calls per minute is just inconsiderate of them. A two minute search finds https://www.alphavantage.co/premium/ but you know, why do it yourself when others will do it for you.
So I was asking for the premium pricing and you give me a website that gives no useful information. I'm not going to e-mail them for pricing, it's 2018. They advertise their stuff as 'free' and to democratize data (another fluff word). So yes, I was thinking they offer an usable service. That's clearly misleading to anyone seriously interested.
The following are free: Quandl Alpha Vantage Both are excellent. I access both using Python but there are other options. You can still use Yahoo easily enough if you are adept in Python using the following library: import fix_yahoo_finance as yf