Where to parse cryptocurrency rates for free?

Question

API

In general, where do you parse the cryptocurrency rate from?
Now I use the coinapi.io API, 100 requests per day are free, but the rate is updated there only once every 3 hours, can you tell me a free alternative, where at least the rate is updated every 30 minutes, or better, the rate at the time of the request.
Thanks to all.

Answer 1

You go to the exchange where the cryptocurrencies you need (for example , binance ) and with the help of their rest api you get everything you need, the limits are very large (a dozen requests per second it seems)
ps I remind you that the exchange rate is an abstract thing, you will receive either an average value ( either min/max) on the interval, or the value in the past