description: An overview of public testnets that you can test Ocean Protocol applications against.
---
You can test an Ocean Protocol application (such as a marketplace) against some testnets that are maintained by the Ocean Protocol Foundation and others.
## Kovan Testnet
The [Kovan Testnet](https://github.com/kovan-testnet/proposal) (or just "Kovan") is a public Ethereum testnet operated by members of the Ethereum community. The Ocean Protocol [keeper contracts](https://github.com/oceanprotocol/keeper-contracts) (smart contracts) are deployed there.
Moreover, there is a [Secret Store](/concepts/components/#secret-store) operated by the Ocean Protocol Foundation which is connected to the Kovan Testnet.
The Nile Testnet is similar to the Kovan Testnet, except all the nodes are operated by the Ocean Protocol Foundation. The Ocean Protocol [keeper contracts](https://github.com/oceanprotocol/keeper-contracts) (smart contracts) are deployed there.
Moreover, there is a [Secret Store](/concepts/components/#secret-store) operated by the Ocean Protocol Foundation which is connected to the Nile Testnet.
When Ocean Protocol developers run [Barge](https://github.com/oceanprotocol/barge) with the `--local-spree-node` option, a "Spree Testnet" node is deployed on their local machine: a local "testnet" not connected to any public testnet. It's named after the main river flowing through Berlin, Germany, where many Ocean Protocol developers are located.
- [Details about the Nile Testnet](https://github.com/oceanprotocol/dev-ocean/blob/master/doc/devops/secret-store-cluster.md) (which is called the "Parity Secret Store Cluster" on that page).
- [Addresses of the keeper contracts](https://github.com/oceanprotocol/keeper-contracts#testnet-deployment) (smart contracts) deployed in the public testnets (and more).
