Established in 2013 as the first cloud mining provider, CEX.IO has become a multi-functional cryptocurrency exchange, trusted by over a million users.

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Changelly is another really decent exchange where users can exchange dollars for a wide range of cryptocurrency from bitcoin to dogecoin. It will search for the best exchange rate and then purchase them for you. Its basically an instant cryptocurrency exchange which has some of the best crypto-to-crypto rates on the market.

Coinbase is a digital currency exchange headquartered in San Francisco, California.They broker exchanges of Bitcoin, Bitcoin Cash, Ethereum, and Litecoin with fiat currencies in around 32 countries, and bitcoin transactions and storage in 190 countries worldwide.