Ethereum Testnets Update Ahead of The Merge for Infura Developers

As we approach the Merge, we at Infura wanted to give you an update about what testnets will be supported in order for you to understand what’s available for you when testing your own infrastructure. Building on an informative article, History of Testnets, this blog defines the future of the Ropsten, Kovan, Rinkeby, Görli, Sepolia testnets as it relates to Ethereum’s merge to Proof-of-Stake this summer. Below, you will find a description of the various Ethereum Execution Layer testnets and the current knowledge on what will happen with each as part of the Merge.

| Testnet | Will it merge? | What will it merge with? | And then? |
|---|---|---|---|---|
| Ropsten | Yes, it merged at Total Terminal Difficulty 50000000000000000 | A new Ropsten beacon chain, named Ropsten | It will be deprecated by end of year: https://twitter.com/TimBeiko/status/1534580444221431810 |
| Kovan | No | Nothing | It will no longer have anyone supporting it, and will be deprecated |
| Rinkeby | No | Nothing | It will no longer have anyone supporting it, and will be deprecated. |
| Goerli | Yes | The Prater testnet beacon chain | Will still be used; anyone can be a validator on this testnet |
| Sepolia | Yes | A new beacon chain, presumably named "Sepolia" but name of that beacon chain is to be determined | Will be the primary testnet |

Ropsten

Ropsten is the oldest testnet that is currently active and uses Proof-of-Work (mining) for new blocks. So, it is also the testnet that is technologically closest to Mainnet (for a more in-depth history of Ropsten and the predecessor testnet Morden, we encourage you to read EIP-225: Clique proof-of-authority consensus protocol by Péter Szilágyi). However, since it uses mining, it's also entirely reliant on miners to produce blocks. As such, the plan is for Ropsten to be deprecated after the Merge. However, since it's the oldest testnet with a lot of data on it, the community (by “the community”, we mean the participants in the All Core Devs calls and discussions and the Eth R&D Discord, with support from Ethereum Cat Herders, Ethereum Magicians, and other teams and individuals who participate in the governance of Ethereum) decided to go ahead and execute the Merge on Ropsten, and then deprecate it by end of year, as a dry run for the other testnets.

What should I do if I’m currently using Ropsten for testing purposes?

Ropsten will work for a bit longer, but it is starting to go away. You should begin using another testnet if you are currently using Ropsten. Ropsten can go through periods of no block production, so always be prepared to use another testnet or a locally run blockchain like Ganache for testing purposes if that occurs. Some time after the merge of mainnet Ethereum and the Beacon Chain, Infura will announce that we will be removing the Ropsten endpoints from our platform, and we will give you a timeframe for when those endpoints will be deprecated.

Kovan

Kovan was announced on March 6, 2017, as a response to the February 24, 2017 Denial-of-Service attacks on Ropsten. It's a Proof-of-Authority (PoA) network, meaning that only certain entities can produce new blocks. Merge support is not planned for OpenEthereum and Kovan will no longer be supported, as it will stop getting new EIP updates.

What should I do if I’m currently using Kovan for testing purposes?

Make preparations to switch to using another testnet if you are using Kovan, it will not be supported after the Merge. So, at some time in the future, Kovan will no longer produce blocks and will not be usable as a testnet. Infura will announce when we will be removing the Kovan endpoints from our platform and give you a timeframe for when those endpoints will be deprecated.

Rinkeby

In order to solve the challenges presented by malicious actors attacking the Ropsten, the Clique Proof-of-Authority (PoA) consensus mechanism was developed, along with the Rinkeby network on which to run this consensus mechanism.

The Geth team has done a lot of work in order to maintain Rinkeby, but with the release of Geth 1.10.18, Rinkeby is now officially deprecated. Péter Szilágyi has encouraged the community to deprecate this tesnet with an eye to “clean(ing) up stuff” (see tweet thread).

What should I do if I’m currently using Rinkeby for testing purposes?

Make preparations to switch to using another testnet if you are using Rinkeby. Rinkeby will not be supported, so at some time in the future, it will no longer produce blocks and will not be usable as a testnet. Infura will announce that we will be removing the Rinkeby endpoints from our platform and give you a timeframe for when those endpoints will be deprecated.

Görli (Goerli)

Clique became a bit of a standard with regard to testnet consensus mechanisms and Görli (which will be written as “Goerli” for the rest of this article) was created to have a Clique PoA network, where many participants can run signers. For example, Infura runs one of those Clique PoA network signers. Clique is supported in Besu and in other non-Geth clients now, as well.

The current plan is for Goerli to merge with Prater (the beacon chain testnet) and keep going. The “little umlaut that could” (pardon the pun) will persist as a supported testnet. Interestingly, since anyone with 32 Goerli ETH can be a validator on Prater, that means that Goerli will go from a "permissioned" PoA network where the block producers are explicitly assigned, to a fully "open" one.

What should I do if I’m currently using Goerli for testing purposes?

Continue to use Goerli. The Goerli endpoints will remain on the Infura platform as a supported testnet, once Ethereum successfully merges to effect the Proof-of-Stake consensus mechanism.

Sepolia

Sepolia is the newest testnet, but is actually over seven months old. The plan is to merge Sepolia with a new beacon chain, potentially of the same name. Interestingly, in this transition, Sepolia will go from "PoW anyone can mine" to "only these validators are allowed", much like the old PoA setup, but using a beacon chain for consensus rather than Clique/Aura.

Infura will announce when users will have access to Sepolia endpoints.

Once we have the relevant endpoints available for use, we encourage those who have a need to use an Ethereum testnet, to use Sepolia. The Sepolia endpoints will be displayed similarly to how other testnet endpoints are currently displayed on the Infura platform. We will make an announcement and provide updated documentation when the Sepolia endpoints become available on Infura. Please follow us on Twitter or follow this blog, for more details.

What about L2s and non-Ethereum Virtual Machine compatible networks?

There are no current impacts to L2s or non-EVM chains related to the Merge, but if new information becomes available or relevant, you can find it on our Twitter or follow this blog

As always, this is an evolving space, so we will update and/or link out from this post as more specific information becomes available or changes to this plan occur. You can stay up-to-date with all things related to the Merge from an Infura or ConsenSys product perspective, here.

I need a refresher on using testnets!

If you need a refresher on using testnets, check out our docs for tutorials, which will walk you through sending API requests, getting testnet ETH, and deploying a dApp (smart contract and a front-end) . Follow us here, for updates.

I have read this far - where do the names of the testnets come from?

Train stations. Typically it is related in some way to those who were part of the development team(s) or an event that may have occurred (like the Amphora Interop event in Greece). Each link below is to information on the respective train station, going back to the first testnet, Morden.

• Morden Tube Station, London, United Kingdom
• Ropsten Metro Station, Stockholm, Sweden
• Kovan Metro Rapid Transit (MRT) Station, Singapore
• Rinkeby Metro Station, Stockholm, Sweden
• Görlitzer Bahnhof, Berlin, Germany
• Sepolia Train Station, Athens, Greece