Ethereum: Glamsterdam upgrade advances from devnets to public testnets - Sep 2026

Ethereum's Glamsterdam upgrade has moved past its devnet phase, with testnet networks now forking ahead of an expected mainnet deployment. According to the announcement, Glamsterdam's testnet forks confirm the major scaling upgrade remains on schedule for a planned mainnet activation later in the year.The upgrade targets a more than threefold increase in Ethereum's gas limit, a material expansion of base-layer capacity. Testnet forking de-risks the core ETH fee-and-burn thesis by showing the scaling path is progressing on schedule before mainnet activation. The decisive catalyst remains the mainnet activation itself, since testnet readiness does not guarantee final deployment timing.