How BNB Smart Chain finalises a block

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Just sealed

pending transaction sealed block, and the in-turn validator's ring block relay and finality votes finalised succeeded reverted, fee still paid the block's real sealer votes, replayed (not observed)

Wallets send signed transactions to any node, which keeps them in its mempool and passes them on. Most reach the validators within a fraction of a second.
Validators take turns in address order, eight blocks each. The one whose turn it is (ringed) packs the block and signs its header; this is block 1 of 8 of its turn. The next in line is ringed faintly.
The sealer sends the block to its peers, who check the signature, that it was really this validator's turn, and every transaction, then pass it on.
Each validator signs a BLS vote for the block it just imported and broadcasts it. Once more than two thirds have voted the block is justified. Votes: 0 of 15.
The next sealer packs the votes, aggregated into one signature, into its own header. When a justified block's child is justified too, the parent is final: it can't be reverted without a third of the validators being slashed.
The sealer collects the block's fees in a system transaction at its end; a tenth is burned and the rest is shared with the stakers who delegated to it. Then the next block starts, 0.45 seconds after the last.

The sealer and finality are real: each header names its sealer, and the node reports the newest finalised block. Relay and votes happen between validators, so the blue bursts are a replay. Pick any step to study it in step-by-step mode.

Transaction types, by share of each block Waiting for the first full block

How this is counted

Every transaction in a block counts once, whether it succeeded or reverted. A transfer of BNB has no call data; a contract creation has no recipient; a BEP-20 transfer calls transfer(address,uint256); a system transaction is the sealer paying itself and the system contracts at the end of the block; everything else is a contract call.

Transactions per block Waiting for the first block

succeeded
reverted (fee paid)
before you connected

BNB Smart Chain blocks 0 tx in this block 0.000000 BNB burned 0 sealing of 0 elected · 0 BNB staked – blocks to finality

The parts that make this work

Proof of Staked Authority

BNB Smart Chain runs an Ethereum-style EVM, but its consensus, called Parlia, is closer to a rota than a lottery. Anyone can register a validator by self-staking at least 2,000 BNB, and holders delegate BNB to the validators they back. Once a day the staking contract ranks them by total stake and elects up to 45. When this page was built, 56 validators were registered with about 25 million BNB between them, and the largest held about 1.3 million. Stake buys a place in the set, not a bigger share of blocks: inside the set every sealer gets the same number of turns.

Epochs and turns

The chain is divided into epochs of 1,000 blocks. At each epoch boundary a validator-set contract picks the 21 validators that will seal blocks in it: most come from the top of the elected list (the "cabinet"), and a few are drawn from the rest (the "candidates"), so smaller validators still get to produce and stay in practice. Within an epoch the sealers are ordered by address and take turns of eight consecutive blocks each. The turn-holder is "in turn" and signs with difficulty 2; if it's offline, any other sealer may sign the block "out of turn" after a short wait, with difficulty 1, so the heavier in-turn chain wins any fork.

Fast finality

A rota alone only gives probabilistic finality: you wait until enough later blocks pile on. Since 2023 (BEP-126) validators also vote. After importing a block, each signs a vote for it with a BLS key and broadcasts it. When more than two thirds of the validators have voted for a block it is justified, and the next sealer writes the aggregated signature into its header. A justified block whose direct child is also justified is finalised. In practice the finalised block trails the head by one or two blocks, under a second. A validator that votes for two conflicting blocks at the same height can be reported and slashed.

From 3 seconds to 0.45

BNB Smart Chain launched in 2020 with 3-second blocks and 21 validators. A run of hard forks has cut the block time since: Lorentz to 1.5 seconds and Maxwell to 0.75 seconds in 2025, then Fermi to 0.45 seconds on January 14, 2026. Later 2026 upgrades, Osaka/Mendel in April and Pasteur in August, kept the 0.45-second block and tuned finality and how much fits in each block.

Fees and burning

BNB Smart Chain uses EIP-1559 fields but keeps the base fee at zero, so a transaction pays its gas at the price it bids, a small fraction of a gwei on a quiet chain. The sealer doesn't get the fees directly: the last transactions in each block are system transactions in which it deposits the block's fees with the validator-set contract. A tenth of that deposit is burned on the spot (BEP-95), a small slice funds system rewards such as relayer fees, and the rest is paid out to the validator and its delegators. The burn shown on this page is that tenth, worked out from each block's receipts. BNB also has a separate quarterly auto-burn, which this page doesn't count.

What live mode shows

Live mode subscribes to new block headers over a public WebSocket and fetches each block, its receipts and the newest finalised block over JSON-RPC. Block numbers, hashes, transaction counts, gas, the succeeded and reverted split, fees, and the BNB burned are all real. So is the sealer: each header names it, and its ring on the scene is the validator that really signed the block. The ring itself is the 21 validators sealing in this epoch, read from the validator-set contract in address order, which is the order turns go round, sized by the voting power the staking contract reports. Finality is the gap between the head and the node's finalised block. What isn't public is the relay and the votes before they're aggregated, so the blue bursts are a replay timed to each real block.

What the animation simplifies

The real chain produces a block every 0.45 seconds, far too fast to follow, so step-by-step mode stretches one block over about a dozen seconds. In reality voting for one block overlaps with sealing the next, and every block carries the votes for its parent. Gossip, vote timing and fee sizes are illustrative. The protocol details are in the BNB Smart Chain documentation and the BEP repository.