The process of phasing out Ethereum’s Ropsten and Rinkeby test networks (testnets) starts Wednesday when blockchain explorer Etherscan shuts down its infrastructure support for them. This means developers should move their testing activities over to Goerli and Sepolia testnets as soon as possible.
Ethereum runs testnets for developers to test new software before launching it on Ethereum’s main network, or mainnet. Test networks are essentially copies of the Ethereum mainnet, and they allow developers to analyze any changes to their applications in a low-stakes environment before applying them.
The Ethereum Foundation announced that Ropsten would be "deprecated" in the fourth quarter of 2022, and Rinkeby would be phased out in the second quarter of 2023. However, infrastructure providers like Etherscan, which is one of the most-used block explorer and analytics platforms for the Ethereum blockchain, have the option to stop supporting the networks earlier.
Rinkeby did not go through a test Merge, though Ropsten did (meaning it transitioned from proof-of-work to proof-of-stake) on June 8, 2022. Users of these testnets will switch over to either the Sepolia or Goerli testnets.
The Sepolia and Goerli testnets also ran through their own test Merges over the summer.
“Sepolia and Goerli are considered the two testnets the ecosystem plans to support,” said Parithosh Jayanthi, a DevOps Engineer at the Ethereum Foundation, to CoinDesk. “Goerli has a relatively large dapp (decentralized applications) ecosystem and allows users to join the validator set in order to test their staking setups. Sepolia is a relatively new testnet and has a small state size, making it easy to use for experimentation,” Jayanthi added.
Ethereum’s mainnet Merge was successfully completed on Sept. 15.
Read more: Ethereum After the Merge: What Comes Next?