‘Millisecond’ preconfirmations make it to Ethereum via new RPC

Ethereum transactions can now be preconfirmed in just a fraction of a second with new tech from an Ethereum infrastructure platform.

Primev says its FAST RPC (Remote Procedure Call) allows transactions to be preconfirmed and set for inclusion in blocks in under 200ms — enabling everything from Ether (ETH) transfers and interacting with smart contracts to minting non-fungible tokens (NFTs) at “blazing speed.”

Preconfirmation is an early signal from a block builder indicating a transaction will likely be included in the next block, while block inclusion refers to a transaction being added into a block.

RPCs like FAST RPC connect crypto wallets to blockchain nodes, enabling users to send transactions and interact with decentralized applications onchain.

From the user’s perspective 200ms could theoretically rival high-speed layer 1 blockchains like Sui, where transactions are usually confirmed within 200ms.

Primev’s founder, Murat Akdeniz, posted a live demonstration to X on Monday, showing a near-instant ETH transfer via Ethereum self-custody wallet MetaMask, which he said was preconfirmed in 377ms and included in the same block.

Akdeniz said his team has been working for more than two years to “supercharge Ethereum” to these speeds.

Ethereum L1 is painfully slow 😩

Can devs PLEASE fix this?!?

For 2+ years, the @primev team has been grinding to supercharge Ethereum mainnet.

Today: MILLISECOND preconfirmations… ON L1! 🚀watch me send ETH blazing fast in this 18s vid pic.twitter.com/Diao4VfHzT

— Murat | lordofcoins.eth (@MuratLite) October 20, 2025

FAST RPC hasn’t been tested at scale

The most widely used RPCs on Ethereum are Infura and Alchemy’s solution, which, while slower than Primev’s FAST RPC, have a much larger node distribution and have been battle-tested under much heavier network loads.