The number of blocks produced in the ledger since the genesis block. Block height increments only for slots that successfully produce a block (skipped slots do not increment it), so block height is always less than or equal to the current slot number. Block height is accessible via the getBlockHeight RPC method and the Clock sysvar.
Start with the shortest useful explanation before going deeper.
The number of blocks produced in the ledger since the genesis block. Block height increments only for slots that successfully produce a block (skipped slots do not increment it), so block height is always less than or equal to the current slot number. Block height is accessible via the getBlockHeight RPC method and the Clock sysvar.
Use the quick analogy first so the term is easier to reason about when you meet it in code, docs, or prompts.
Think of it as part of the chain machinery that keeps ordering, execution, or consensus moving.
Place the term inside its Solana layer so the definition is easier to reason about.
Consensus, leader rotation, slots, epochs, and the runtime.
Turn the term from vocabulary into something operational for product and engineering work.
This term unlocks adjacent concepts quickly, so it works best when you treat it as a junction instead of an isolated definition.
Use this compact block when you want to give an agent or assistant grounded context without dumping the entire page.
Block Height (block-height) Category: Core Protocol Definition: The number of blocks produced in the ledger since the genesis block. Block height increments only for slots that successfully produce a block (skipped slots do not increment it), so block height is always less than or equal to the current slot number. Block height is accessible via the getBlockHeight RPC method and the Clock sysvar. Related: Block, Slot, Genesis Block
Use glossary context, relationships, mental models, and builder paths to get structured answers instead of generic chat output.
Optional: paste Anchor, Solana, or Rust code so the Copilot can map primitives back to glossary terms.
The Copilot will answer using the current term, related concepts, mental models, and the surrounding glossary graph.
These branches show which concepts this term touches directly and what sits one layer beyond them.
A set of entries produced by a leader during a single slot. A block contains transactions bundled into entries, each with a PoH hash proving ordering. Blocks are broken into shreds for network propagation via Turbine. Maximum block size is limited by compute units (48M CU cap per block) rather than byte size.
A time window during which a designated leader validator can produce a block. Each slot lasts approximately 400 milliseconds. Slots are numbered sequentially from genesis and grouped into epochs of 432,000 slots (~2-3 days). Not every slot produces a block—a skipped slot means the leader was offline or too slow.
The first block (slot 0) of a Solana cluster that defines initial configuration: the mint account, initial token supply, built-in program deployments, and cluster parameters. The genesis config is generated by the `solana-genesis` tool and shared among all validators to bootstrap a new cluster.
These are the next concepts worth opening if you want this term to make more sense inside a real Solana workflow.
These entries are easy to mix up when you are reading quickly, prompting an LLM, or onboarding into a new layer of Solana.
A set of entries produced by a leader during a single slot. A block contains transactions bundled into entries, each with a PoH hash proving ordering. Blocks are broken into shreds for network propagation via Turbine. Maximum block size is limited by compute units (48M CU cap per block) rather than byte size.
The process of distributing a newly produced block from the leader to all validators in the cluster. Solana uses Turbine for fast propagation—the leader shreds the block, erasure-codes the shreds, and feeds them into the Turbine tree. Target propagation latency is under 200ms for the full cluster.
A block that has received votes from validators representing a supermajority (66.7%+) of the cluster's active stake, achieving optimistic confirmation. Confirmed blocks are highly likely to be finalized but are not yet irreversible — full finality requires the block to become rooted through 31+ consecutive confirmations in Tower BFT.
Glossary entries become useful when they are connected. These links are the shortest path to adjacent ideas.
A set of entries produced by a leader during a single slot. A block contains transactions bundled into entries, each with a PoH hash proving ordering. Blocks are broken into shreds for network propagation via Turbine. Maximum block size is limited by compute units (48M CU cap per block) rather than byte size.
A time window during which a designated leader validator can produce a block. Each slot lasts approximately 400 milliseconds. Slots are numbered sequentially from genesis and grouped into epochs of 432,000 slots (~2-3 days). Not every slot produces a block—a skipped slot means the leader was offline or too slow.
The first block (slot 0) of a Solana cluster that defines initial configuration: the mint account, initial token supply, built-in program deployments, and cluster parameters. The genesis config is generated by the `solana-genesis` tool and shared among all validators to bootstrap a new cluster.
These entries live beside the current term and help the page feel like part of a larger knowledge graph instead of a dead end.
A clock mechanism that cryptographically proves the passage of time between events. PoH uses a sequential SHA-256 hash chain where each output becomes the next input, creating a verifiable ordering of events without requiring consensus. The leader produces ~400,000 hashes per slot (~400ms), and any validator can verify the sequence in parallel, enabling Solana's high throughput by removing the need for validators to agree on time.
Solana's custom BFT consensus algorithm built on top of Proof of History. Tower BFT uses PoH as a clock to reduce communication overhead in traditional PBFT from O(n²) to O(n). Validators vote on forks with exponentially increasing lockout periods—each consecutive vote doubles the lockout, making rollbacks progressively more expensive. A fork is finalized when it reaches supermajority (66.7%+ of stake).
A time window during which a designated leader validator can produce a block. Each slot lasts approximately 400 milliseconds. Slots are numbered sequentially from genesis and grouped into epochs of 432,000 slots (~2-3 days). Not every slot produces a block—a skipped slot means the leader was offline or too slow.
A set of entries produced by a leader during a single slot. A block contains transactions bundled into entries, each with a PoH hash proving ordering. Blocks are broken into shreds for network propagation via Turbine. Maximum block size is limited by compute units (48M CU cap per block) rather than byte size.