Priority Fees, Block Building and Where Your Tip Goes

The priority fee is described in most guides as a tip to the validator. That was accurate once and is now a simplification that hides the more interesting structure.

The modern path

Most blocks today are not assembled by the validator proposing them. They are assembled by specialist builders who compete to produce the most valuable block, and validators select the highest-paying one through an intermediary.

So the path is: your transaction enters a public pool or a private channel, builders include it if profitable, the builder pays the validator for the right to have their block proposed, and the validator collects.

Your priority fee is one input into whether a builder includes your transaction. It is not the only one.

Why that matters for what you pay

Ordering within a block has value beyond your tip. A builder may place transactions in an order that generates additional revenue through arbitrage or liquidation opportunities. That revenue competes with and sometimes outweighs the tips being offered.

A higher tip does not guarantee earlier placement. It improves your odds. Placement is determined by the builder’s overall optimisation, not by a simple ranking.

Some transactions pay nothing visible and are still included. Arrangements exist where the value accrues to the builder through other means.

The practical consequences for an ordinary user

Slippage protection matters more than fee level. If a swap can be sandwiched, the cost of that is typically larger than any fee saving from tuning the tip. A tight slippage setting is the defence.

Private transaction routing exists and is worth knowing about. Several wallets and services allow transactions to be sent directly to builders rather than broadcast publicly. This reduces exposure to front-running because the transaction is not visible in the public pool before inclusion.

For large swaps this is a genuine protection. For a routine transfer it makes no difference.

Failed transaction costs are unaffected by any of this. A revert still costs the gas consumed.

What a tip actually buys during congestion

During quiet periods, almost nothing. The base fee is the binding constraint and inclusion is near-certain in the next block or two regardless of tip.

During congestion, the tip is what determines whether you are included now or in twenty minutes. That is the period when the speed setting in a wallet has a visible effect.

Why this is not a problem you can solve by paying more

Transaction ordering value is extracted by participants with better infrastructure, faster connections and direct relationships with builders. An individual user cannot outbid that, and attempting to do so simply raises the cost of the trade.

The defences are structural rather than financial: tight slippage limits, private routing for anything substantial, and avoiding thin pools where the extractable value is largest relative to trade size.

For anyone whose activity is buying and holding rather than trading on-chain, none of this applies. Purchases made through an exchange are matched internally, and venues that quote the network fee separately charge a stated fee with no ordering auction involved. The entire category of concern described here is specific to on-chain execution.