TL;DR
- Developers are encouraged to migrate testnets from Goerli to Sepolia
- Goerli faucets are drying up, and Goerli ETH is becoming more precious
- It may be wise to carefully plan out the usage of your remaining Goerli ETH
Brief History of Testnets
Ethereum has gone through many test networks over the years, including:
- Olympic (very first public Ethereum testnet, Proof of Work, 2015)
- Morden (Proof of Work, 2015-2016)
- Ropsten (Proof of Work, 2016-2022)
- Kovan (Proof of Authority, 2017-2022)
- Rinkeby (Proof of Authority, 2017-2023)
- Goerli (Proof of Authority, 2018-2023)
- Sepolia (Proof of Stake, 2021-)
- Other smaller testnets, including the Kintsugi and Kiln Merge Testnets, which were created for testing client implementations before The Merge
In September 2022, Ropsten, Sepolia and Goerli all merged with their respective Beacon (Proof-of-Stake) chains to shift to a Proof-of-Stake consensus mechanism, acting as a “dress-rehearsal” for The Merge on Ethereum mainnet.
Current Testnets in Use: Goerli and Sepolia
Though Goerli deprecated in January 2023, support will continue for the rest of the year. Sepolia, and Goerli despite its deprecation, are two testnets that are recommended for use as older testnets lose their support over time. Rinkeby will no longer have protocol upgrades and Ropsten will experience interruptions and downtime due to big service providers shutting down their testing infrastructure.
While developers are encouraged to transition to Sepolia, Goerli is still suggested for stakers to test protocol upgrades and developers who want to interact with a large existing state. Sepolia is recommended for users and developers who want a lighter-weight chain to sync to and interact with.
https://blog.ethereum.org/2022/06/21/testnet-deprecation
The Impact
With Goerli faucets running low on supply, it is becoming harder to get Goerli ETH. Normally, a test token is distributed for free through faucets and does not get traded between testnets and mainnet. Goerli ETH's scarcity, however, resulted in the creation of an active market for the token with the price shooting up to a high of $1.60 in February 2023. The price of Goerli ETH has dropped down since then, but it continues to be traded like a real token.
Test tokens were never meant to be traded like real tokens. What usually makes testnets risk-free is that their token, like Goerli ETH, is essentially “play money.” Developers on a test network can experiment, test and make errors without losing real cryptocurrency funds. Goerli, like other testnets, was never intended to be incentivised. Even the initiator of the Goerli testnet project has expressed frustration about the direction things have taken.
Many projects which were testing on Rinkeby and Kovan just recently migrated to Goerli. Having them migrate once again to Sepolia can be another project in and of itself. So until developers have the resources and capacity to make the move, testing will continue on Goerli.
Sepolia Faucets
There is an uncapped supply of Sepolia ETH and faucets are currently dispensing reasonable amounts of the token.
Goerli Faucets
Goerli only has 115M GoETH total supply. Because of the scarcity, many faucets are dispensing very small amounts of Goerli ETH with varying constraints.
Further Reference
https://ethereum.org/en/developers/docs/networks/
https://ethereum.org/en/roadmap/merge/
https://archive.devcon.org/archive/watch/6/post-merge-testnets/?tab=YouTube
https://dev.to/5chdn/the-grli-testnet-proposal---a-call-for-participation-58pf
https://blog.ethereum.org/2022/06/21/testnet-deprecation
https://blog.chainsafe.io/ethereum-testnets-goerli-eth-and-a-way-forward-265b02258700
https://consensys.net/blog/news/the-history-of-ethereum-testnets/
https://docs.chainstack.com/docs/goerli-to-sepolia-transition
https://www.alchemy.com/overviews/what-are-testnets