Ethereum's Glamsterdam upgrade will activate on the Hoodi test network at 17:42:48 UTC on October 26, the Ethereum Foundation says. The activation lands at Hoodi epoch 132,352, slot 4,235,264 — and it comes with a jump in the testnet's gas limit, which will rise to 200 million at the same moment. There's no mainnet date. That's the part builders and node operators are watching.
What Glamsterdam actually changes
Glamsterdam is a big one on the protocol side. It brings enshrined proposer-builder separation, or ePBS, which drags the proposer-builder relationship directly into Ethereum's protocol instead of leaving it to out-of-protocol middleware. It also adds block-level access lists, designed to let clients process and validate parts of a block in parallel. Gas accounting gets a rework too, including how the network charges for state creation and access.
In plain terms: this is plumbing. The kind of plumbing that changes how blocks get built, priced, and checked. Glamsterdam already ran on Sepolia on October 6, so Hoodi is the next stop, not the first.
The 200 million gas limit isn't a mainnet promise
Hoodi's gas limit jumping to 200 million is the number that will get screenshotted. It shouldn't be read as a mainnet capacity guarantee. A 200-million gas limit on a test network doesn't mean mainnet throughput instantly quadruples. Testnets are for stress, not for promises.
That distinction matters because the mainnet timeline is still blank. Ethereum hasn't announced a mainnet activation date for Glamsterdam, and until it does, the Hoodi run is a rehearsal with real clients and real validators — not a launch date in disguise.
What Hoodi operators need to do
Validators and node operators on Hoodi will need compatible execution and consensus clients before the October 26 activation. If your clients aren't upgraded, you don't participate cleanly. That's the whole job between now and then.
For everyone else? Mainnet users have no action to take yet regarding Glamsterdam. No wallet changes, no migration, no bridge. Not this week.
The date to circle
The concrete thing on the calendar is 17:42:48 UTC on October 26 — Hoodi epoch 132,352, slot 4,235,264. After that, the open question is when the Ethereum Foundation names a mainnet activation slot. It hasn't yet, and the Hoodi gas limit number won't answer it.
