Ethereum’s next major upgrade, dubbed Glamsterdam, hit its final devnet stage on Tuesday. The EIP bundle is locked, and core developers expect the fork to move through public testnets before activating on mainnet in the second half of 2026. The release is being framed as the largest protocol change since a previous unspecified upgrade, and it targets a 200 million gas limit — a significant increase that would boost the network’s throughput.
What’s in the bundle
The exact EIPs haven’t been detailed in the public materials provided, but the bundle is now final. That means no more last-minute additions or cuts. For a change this size — developers are calling it the biggest since Ethereum’s last major overhaul — locking the scope early is a deliberate move to avoid delays. The 200 million gas limit target is the headline number: it’s a roughly 2.5x increase over the current 30 million gas limit, though the exact mechanics and implications for block sizes and fees will become clearer once the testnet data rolls in.
Timeline and next steps
The devnet stage is the first proving ground. Tuesday’s milestone means the code is stable enough for internal testing across multiple client implementations. From here, the upgrade will hit a public testnet — likely Sepolia or Goerli — where node operators and dapp developers can run their own tests. The core team hasn’t given a specific date for mainnet, but the H2 2026 window puts it sometime between July and December. That’s a deliberately wide range; Ethereum’s past upgrades have slipped by months when bugs emerged late in testing.
Why the gas limit matters
Raising the gas limit to 200 million is a bet on scalability without a full layer-2 migration. It allows more transactions per block, which could lower fees for users on L1 — but it also increases the resource demand on validators and node operators. Bigger blocks mean more data to propagate and store. The upgrade will test whether the network can handle that load without centralizing pressure on large stakers. If it works, Ethereum gets a meaningful throughput boost. If it doesn’t, the next hard fork will probably walk the limit back.
Unanswered questions
The biggest unknown is how the upgrade interacts with existing L2 rollups. If L1 gas gets cheaper and faster, some activity might shift back from L2s to mainnet — that’s a dynamic no one can model until the fork is live. The devnets will give early signals, but the real data won’t come until after mainnet activation. Developers will be watching testnet participation closely over the next few months. The first public testnet launch is expected within weeks.
