The sandbox ecosystem is developed onto the Ethereum blockchain.
Other related questions:
Q: What blockchain is Sandbox on?
A: Sandbox is on the Ethereum blockchain.
Q: Is SAND built on Ethereum?
A: Yes, SAND is built on the Ethereum blockchain.
Q: Will Sandbox be listed on Coinbase?
A: There is no current listing for Sandbox on Coinbase.
Q: What is$ SAND Sandbox?
A: SAND Sandbox is an isolated testing environment that allows you to safely test and experiment with new code or changes to existing code without affecting live systems.