Ethereum’s Sepolia Testnet Merge Success, Goerli Next

6 min readJul 25, 2022


ethereum testnet merge

Table of Content:

  1. What is Sepolia Testnet
  2. What makes it unique
  3. Ethereum Sepolia Testnet
  4. What’s Next — Goerli
  5. Final Thoughts

On July 6, Ethereum developers completed The Merge on the Sepolia testnet, taking the Ethereum network further to the Proof-of-Stake (PoS) network.

Sepolia’s proof-of-work chain, combined with the proof-of-stake beacon chain, is now the execution layer.

Anthony Sassano confirmed the success of The Merge on the Sepolia testnet. He added that it also paves the way to implement The Merge on the Goerli testnet. On his Twitter timeline, Sassal wrote:

“Thanks to everyone who watched the Sepolia merge on Livestream!!

The Sepolia merge transition went through successfully (and the chain was finalized!), so now it’s time for monitoring over the next few days.

Then we merge Goerli…

…then mainnet.

The Merge is coming.”

Sepolia merge tweet

In this post, we’re going to explore what Sepolia testnet is, what makes Sepolia Testnet unique, and what’s next in the row...

Let’s get started!

What is Sepolia testnet?

ethereum testnet faucet

Ethereum core developers built Sepolia in October 2021 as a proof-of-work tesnet. After the Ropsten testnet reaches a Terminal Total Difficulty (TTD) of 50000000000000000, proof-of-stake Sepolia and the Goerli testnet will switch to a proof-of-stake consensus mechanism to echo the Ethereum mainnet.

Ethereum core developer Tim Beiko says that once Ropsten, Goerli, and Sepolia have forked and stabilized the development team, the date can be set for completing the Ethereum Merge.

Testnets are parallel blockchains that mimic the operating environment of a ‘mainnet’ but are distinct ledgers. Using a testnet, core developers can experiment with the merge, and application developers can check how their apps will function in the future after the Ethereum main net merge without incurring financial losses through testing in Ethereum’s production environment.

What makes Sepolia Testnet unique?

Public testnets such as 50% of the ether in the Kovan testnet are controlled by public validators. Sepolia is a testnet that is open to the public, and where almost all of the ether is controlled by public validators.

Because these public validators have not undergone any background check or capability testing by network participants, they may fail to have the necessary hardware and software to stay connected to the testnet at all times, and the chain will therefore not finalize.

Ethereum’s Sepolia testnet

The Ethereum network has numerous tests running in the development environment called testnets. Testnets simulate real-world conditions and provide feedback on proposed changes before they go live on the main net.

The largest and most popular test net is Ropsten, named after the Ethereum founder Vitalik Buterin who first deployed the code. The other two major platforms running various tests are Rinkeby and Kovan. And now, Sepolia, launched earlier this year as a private test net, has also implemented the Merge upgrade.

Ethereum’s public testnet Sepolia is now the second major testnet to implement the long-awaited Merge upgrade. This brings the entire protocol closer to changing its consensus mechanism from proof of work (PoW) to Proof of Stake (PoS).

When the upgrade was executed, the Sepolia POW chain was “merged” with the beacon chain. The beacon chain or “consensus layer” was released in December 2020 and may still only be staked ETH.

The upgrade on the POW network was initiated at approximately 2 pm UTC on July 6, after which the upgrade process was coordinated among node operators on both chains.

Investors received temporary relief as the ETH price rose 5% in the last 24 hours and is currently trading at $1,170. The world’s second-largest cryptocurrency has suffered significant selling pressure this week.

However, the positive development is certainly reigniting investors’ hopes again.

Source: Santiment

No Delay In the Mainnet Merge

Ethereum 2.0 development has seen partial delays in the past due to the proof-of-stake transition. The Ethereum mainnet transition is expected to happen by the end of the year. Even with The Sepolia testnet Merge, there were some problems.

Ethereum protocol developer Terence Tsao considered the Merge a “success.” He said 25–30% of validators went offline after the Merge, presumably due to “incorrect configurations.” When the mainnet Merge is delayed due to “minor hiccups” like these, Tsao says, “it’s a success.”

The efficiency of the current Ethereum network is both its energy consumption and transaction speed. At the moment, it’s not unusual to see Ethereum transactions fail. Over 1 million transactions that had already been paid for failed to process in May alone. The transition to proof of stake is expected to make the network much more efficient.

Corporate capture is a serious problem with the current model of smart mining. Because of this, Bitcoiners are less likely to switch to a POS system than others. In addition, CFTC chief Rostin Benham wants to encourage this switch through smart mining regulation and incentives.

What’s next– Goerli

goerli faucet

PoS is set to be implemented in Goerli’s public testnet in the next three to four weeks, setting the stage for Ethereum’s mainnet to merge in September. Goerli’s move to PoS might take place in the next three to four weeks, setting the stage for Ethereum’s mainnet to merge.

Görli is the first proof-of-authority cross-client testnet, synching Geth, Nethermind, Hyperledger Besu, and others. It is a community-based project and is completely open-source. In September 2018, during ETHBerlin, it was born as the first Goerli testnet. Since then, it has grown in contributors.

The Goerli testnet will be merged with the Prater proof-of-stake beacon chain to conclude the permission proof-of-authority phase. From this point forward, everyone can run a validator for Goerli. Because of this, this repository houses both Goerli’s execution-layer configurations and Prater’s consensus-layer configurations.

Final Thoughts

Ethereum 2.0 development has seen partial delays in the past due to the proof-of-stake transition. The Ethereum mainnet transition is expected to happen by the end of the year. Even with The Sepolia testnet Merge, there were some problems.

The PoW network is prone to attacks and emission of bad actors, while the PoS network is less prone to attacks. With the Goerli network, it will be possible to switch the network to PoS without having to wait for Ethereum’s mainnet.

When the upgrade is implemented on the mainnet, there will be more block producers on the network. The more block producers there are on the network, the more secure and reliable the network will be.

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