The Sepolia testnet Beacon Chain has reportedly officially gone live, paving the way for its merge dress rehearsal to offer Ethereum network developers valuable technical insights.

Specifically, together with the merge with its dedicated Beacon Chain, the Sepolia testnet is reportedly going to achieve consensus via the use of proof of stake (PoS) instead of proof of work (PoW), which will offer data on the possible scenario taking place when the Ethereum mainnet performs its merge.

Testnet merges are of crucial nature for Ethereum engineers and independent project developers utilizing the Ethereum network to grasp a better understanding of the scenario they can expect when the actual merge commences. 

Similar to the environment on the testnets, the Ethereum mainnet merge will witness a complete transition to PoS consensus of the network, and should bring down the energy consumption of Ethereum by 99.9%.

Sepolia was reportedly introduced in October last year. Core Ethereum developer Tim Beiko shared a confirmation in April that the Ropsten testnet would be phased out over time and Sepolia will take its place gradually. Hence, initiatives operating apps on Ropsten have been urged to carry out their migrations of current work over to Sepolia to avoid complications.

Public testnets such as Sepolia and Ropsten are reportedly created to function as replicating tools of the operating conditions of their respective mainnets, which cause no impact to the live mainnet. 

Ropsten is the originially introduced testnet, available since 2016. It underwent its merge on June 8, which was the first example of a merge trial conducting for Ethereum.

The official merge date on the Ethereum mainnet has been delayed a few times. It is now commenced for finalization by August this year, but that date could be pushed back further because of a separate delay in the difficulty bomb. As soon as it completes, it will spawn the Consensus Layer, formerly known as Ethereum 2.0.