The Ethereum Foundation has officially announced the mainnet deployment of the London upgrade, one of the most anticipated network updates in Ethereum’s history. Posted by core developer Tim Beiko on July 15, 2021, the announcement confirmed that London will go live at block 12,965,000, expected to be mined between August 3 and August 5, 2021.
TL;DR
- Ethereum London upgrade confirmed for block 12,965,000, expected August 3-5, 2021
- Five EIPs included, headlined by the controversial EIP-1559 fee market overhaul
- All major client releases have been issued with London-compatible versions
- Bug bounties doubled for any London-related vulnerabilities ahead of activation
- OpenEthereum client will be deprecated following the London upgrade
What the London Upgrade Includes
The London upgrade bundles five Ethereum Improvement Proposals (EIPs) into a single hard fork. The centerpiece is EIP-1559, a fundamental change to Ethereum’s transaction fee mechanism that introduces a base fee burned on every transaction, rather than being paid to miners. This has been one of the most debated changes in Ethereum’s history, with some mining pools publicly opposing it due to the reduction in miner revenue.
Alongside EIP-1559, the upgrade includes EIP-3198, which adds a BASEFEE opcode allowing smart contracts to read the current base fee — a critical enabler for DeFi protocols that need to factor gas costs into their logic. EIP-3529 reduces gas refund incentives, closing a loophole that was being exploited for arbitrage. EIP-3541 rejects new contracts starting with the 0xEF byte, reserving that prefix for future opcodes. Finally, EIP-3554 delays the difficulty bomb to December 1, 2021, buying time before Ethereum transitions to proof-of-stake.
Client Releases and Node Operator Requirements
The Ethereum Foundation released updated client versions for all major implementations. Go-ethereum (geth) version 1.10.6, Nethermind 1.10.79, Erigon 2021.07.04-alpha, Besu 21.7.2, and OpenEthereum v3.3.0-rc.4 all support the London upgrade on mainnet. Node operators running any of these clients must upgrade before the fork block.
Miners, in particular, need to take an extra step: because London doubles the effective block gas limit, miners must manually set their gas limit target to twice their current value. For instance, a miner targeting 15,000,000 gas per block would need to adjust to 30,000,000. Failure to do so would result in producing undersized blocks.
OpenEthereum Deprecation and Security Push
The announcement also marked the beginning of the end for OpenEthereum (formerly Parity), which will be deprecated after the London upgrade. The OpenEthereum team is coordinating with Erigon on a transition path for users. Meanwhile, the Ethereum Foundation has doubled all bug bounties for London-related vulnerabilities, specifically encouraging researchers to look for cross-client consensus issues between geth, Besu, Nethermind, OpenEthereum, and Erigon.
Market Context
At the time of the announcement, Ethereum was trading at approximately $1,911, down roughly 4.2% over 24 hours and nearly 10% over the previous week. Bitcoin sat at around $31,780. The broader crypto market had been in a cooling period following the dramatic highs of May 2021, and the London upgrade represented a key narrative catalyst that many analysts believed could help stabilize sentiment around Ethereum’s long-term value proposition — particularly through the fee-burning mechanism of EIP-1559.
Why This Matters
The London upgrade is one of the most consequential changes to Ethereum’s economic model. By burning transaction fees through EIP-1559, Ethereum introduces a deflationary pressure that could fundamentally alter ETH’s supply dynamics. For DeFi protocols, NFT marketplaces, and everyday users, the new fee mechanism promises more predictable gas costs. For miners, it represents a significant revenue reduction. And for the broader Ethereum community, it marks one of the final major upgrades before the network transitions fully to proof-of-stake. The stakes are high, and the countdown to block 12,965,000 is well underway.
Disclaimer: This article is for informational purposes only and does not constitute financial advice. Always do your own research before making any investment decisions.
been waiting for eip-1559 since 2019. the base fee burn alone will fundamentally change eth economics. this is the real deal
the base fee burn turned ETH deflationary during peak gas periods. went from people worrying about infinite supply to paying 2-3 ETH per block in burns
ETH going deflationary during peak gas periods was the real game changer. supply shock + fee burn = rocket fuel
gas_burn_ the deflationary flip happened faster than anyone predicted. within 3 months of london ETH was net negative supply during peak blocks
went from infinite supply fears to burning 2-3 ETH per block overnight. one of the most impactful economic changes in crypto history buried in a hard fork
ethereum london upgrade at block 12965000 with eip 1559 and five eips should cut gas fees
bug bounties doubled and openethereum getting deprecated. the client diversity push is real. smart move before the fork
deprecating OpenEthereum was risky but necessary. one client having >30% share before a hard fork is a consensus failure waiting to happen
rpc_cache has the right take. openethereum had too much share. deprecating was painful but necessary for client diversity
Block 12,965,000 means August 3-5 depending on block times. Set your calendars and make sure your nodes are updated.
EIP-1559 burning the base fee was called supply crushing at the time. turns out the fee market overhaul worked exactly as designed and ETH became deflationary within months
openethereum deprecation was the quiet bomb here. half the eth nodes were running OE and had to scramble to migrate before london hit. chaos
EIP-1559 was called supply crushing at the time and critics said burning base fees would destroy miner incentives. fast forward and ETH went deflationary within months. best upgrade ethereum ever shipped
fork_archaeologist_ the miner抗议 didnt stop it but hash rate did drop 15 percent within a week of activation. short term pain for long term deflationary mechanics
fork_archaeologist_ the miner protest was real though. f2pool publicly opposed 1559 and threatened to fork. turned out they had zero leverage because ETH mining was already marginally profitable post-merge rumors
bug bounties doubled to what, 50k? for an upgrade handling billions in TVL that always felt cheap. one consensus bug and the entire chain halts
Timur A. bug bounty at 50K for an upgrade securing billions was always absurd. ethereum foundation could have offered 500K and it still would have been underpriced relative to the attack surface
OpenEthereum deprecation was the real stress test. ran OE for 2 years and had 9 days to migrate before the fork. besu saved my node
helsinki_node_ besu saved my node too but the real hero was nethermind. anyone running geth-only setups learned client diversity the hard way that week
tim beiko confirming block 12965000 for london was the moment eip-1559 became real. miners protesting couldnt stop it and the base fee burn changed eth economics permanently
block 12,965,000 was the moment ETH economics changed forever. the fee burn fundamentally rewired how we value the network
eip-1559 burning fees instead of paying miners was the biggest ideological shift since the dao fork. no wonder hash rate dropped after london went live
OpenEthereum getting deprecated right after london was brutal. half the node ops I knew were running it and had maybe 2 weeks to migrate before the fork
openeth_ghost deprecating openethereum with 2 weeks notice before london was brutal. half the node ops i knew were running OE and had to scramble to besu or geth overnight