A second Ethereum test network (testnet), known as Sepolia, successfully replicated withdrawals of staked ether (ETH) today, bringing the Ethereum blockchain closer to its highly anticipated Shanghai Upgrade.
The upgrade was triggered at epoch 56832 at 4:04 UTC and finalized at 4:17 UTC (11:17 p.m. ET).
The Shanghai Upgrade will mark Ethereum’s complete transition to a fully functional proof-of-stake network, enabling validators to withdraw rewards earned from adding or approving blocks to the blockchain.
There is one more test, on Ethereum’s Goerli testnet, that is planned before Shanghai goes live.
The test on Sepolia was designed to provide developers with another dress rehearsal of the withdrawals similar to those that will happen on the main Ethereum blockchain. Testnets copy a main blockchain, in this case Ethereum, and allow developers to test any changes to their applications in a low-stakes environment.
Sepolia is the second of three testnets to run through such a simulation. But unlike the previous testnet upgrade that happened earlier this month on Zhejiang, this was on a closed testnet, meaning that only the Ethereum core developers run the validators on this testnet. Sepolia is also the smallest of all three testnets in terms of the number of validators participating on it, making it the least important of all three.
The final testnet upgrade will occur to Goerli sometime in the coming weeks. That would be the final dress rehearsal before the main blockchain is able to process staked ETH withdrawals. Goerli’s testing will also be the most anticipated given that it is the biggest testnet of the three and it mimics the main Ethereum blockchain’s activity most closely.
If the developers continue to run test upgrades three weeks apart, the next testnet upgrade on Goerli would likely occur around March 21, which could likely push the mainnet Shanghai Upgrade into April. If that were the case, there would be a slight delay versus the target of March that Ethereum developers had initially signaled for the release of staked ETH.