Developers should move their applications to the Goerli or Sepolia testnets.

According to a Wednesday blog post from the Ethereum Foundation, the blockchain’s Ropsten testnet is expected to come offline sometime between December 15 and 31st.

Recently, developers have been shying away from use of the bitcoin testnet. Their lack of participation has led to a decline in overall activity on the network.

Ethereum has a few test networks that act as copies of the main network. These are useful for client teams, infrastructure providers and developers to run their applications on before launching them on the main network. Test networks provide an environment in which people who want to test changes to applications can do so without compromising the competitiveness of the application on Ethereum mainnet.

Ethereum will be ending its Rinkeby testnet in mid-2023. Developers will have the time necessary to move their applications over to the Goerli or Sepolia testnets.

Read more: Etherscan Provides Warning Regarding Ethereum’s Ropsten and Rinkeby Testnets

The Goerli and Sepolia testnets both ran through their own tests of the Merge upgrade (which means they transitioned from proof-of-work to proof-of-stake), so they’re the most similar to the environment that the Ethereum blockchain operates under today. As such, those testnets are expected to continue running.

In October, blockchain explorer Etherscan shut down its infrastructure support for Rinkeby and Ropsten. This is a bit concerning because test networks provide a crucial service to blockchain developers who want to ensure their code functions properly.

Ethereum developers are constantly developing new testnets, depending on what upgrades they are trying to test. Last month, Ethereum developers agreed to go live with the Shandong testnet, which will be used to test EIPs for Ethereum’s next big upgrade.