# Sepolia & Holesky Dencun Announcement

DevFeed: [Sepolia & Holesky Dencun Announcement](<https://devfeed.tech/articles/sepolia-holesky-dencun-announcement-17089.md>)

Original publisher: [Read original article](<https://blog.ethereum.org/en/2024/01/24/sepolia-holesky-dencun>)

Author: EF Protocol Support

Published: 2024-01-24T00:00:00Z

Content type: release

Language: en

Sources: [Ethereum Foundation Blog](<https://devfeed.tech/sources/ethereum-foundation-blog.md>)

Topics: [Ethereum](<https://devfeed.tech/topics/ethereum.md>), [releases](<https://devfeed.tech/topics/releases.md>), [Network](<https://devfeed.tech/topics/network.md>), [Protocol (disambiguation)](<https://devfeed.tech/topics/protocol.md>)

Tags: [ethereum](<https://devfeed.tech/tags/ethereum.md>), [network](<https://devfeed.tech/tags/network.md>), [protocol](<https://devfeed.tech/tags/protocol.md>), [protocol-announcements](<https://devfeed.tech/tags/protocol-announcements.md>), [python](<https://devfeed.tech/tags/python.md>), [release](<https://devfeed.tech/tags/release.md>), [releases](<https://devfeed.tech/tags/releases.md>), [update](<https://devfeed.tech/tags/update.md>)

## AI overview

The Ethereum Dencun network upgrade activated on the Goerli testnet and was scheduled for deployment on the Sepolia and Holesky testnets. The upgrade introduces ephemeral data blobs through EIP-4844, also known as protodanksharding, intended to reduce L2 transaction fees. The article lists relevant client releases and upgrade specifications.

## Source excerpt

Important update: since the initial publication of this post, Lodestar has published a new release, v1.15.0, which Holesky users must upgrade to prior to Dencun's activation on February 7th. Additionally, Prysm and Nimbus have both published highly recommended releases for Holesky. Prysm users are encouraged to use v4.2.1, and Nimbus...