getBlocks — Solana RPC Method

getBlocks returns a list of slot numbers that contain confirmed blocks within a given range. Skipped slots are excluded from the result. This is the standard way to discover which slots in a range actually produced blocks.

Parameters

Request

curl -X POST https://api.mainnet-beta.solana.com \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "getBlocks",
    "params": [311857920, 311857930]
  }'

TypeScript (@solana/kit)

import { createSolanaRpc } from "@solana/kit";

const rpc = createSolanaRpc("https://api.mainnet-beta.solana.com");
const blocks = await rpc
  .getBlocks(311857920n, 311857930n)
  .send();

console.log(`Blocks found: ${blocks.length}`);
// e.g. [311857920, 311857921, 311857923, 311857924, ...]

Response

{
  "jsonrpc": "2.0",
  "result": [
    311857920, 311857921, 311857923, 311857924,
    311857925, 311857926, 311857927, 311857929, 311857930
  ],
  "id": 1
}

In this example, slots 311857922 and 311857928 were skipped — no block was produced in those slots.

Common errors

• Range too large — end_slot must be within 500,000 slots of start_slot. Exceeding this limit returns an error.
• Slots too old — if the requested range is older than the node’s available ledger data, the result may be empty or incomplete.
• processed not supported — using commitment: "processed" returns an error. Use confirmed or finalized.

Performance

The response size depends on the range and the skip rate. A 500,000-slot range at a ~5% skip rate returns approximately 475,000 slot numbers. For large ranges, consider using getBlocksWithLimit to paginate results. The 500,000-slot cap (approximately 2.3 days at 400ms slots) exists to prevent excessive load on the node.

FAQ

What is the maximum range I can query? 500,000 slots, which is approximately 2.3 days of Solana time at 400ms per slot.

Why are some slots missing from the result? Missing slots are skipped slots — no validator produced a block in that slot. This is normal; Solana’s skip rate is typically 3-8% on mainnet.

How do I scan the entire ledger? Paginate using 500,000-slot windows. Set start_slot to the end of the previous range + 1 and call again. Alternatively, use getBlocksWithLimit which returns a fixed number of results starting from a given slot.

What is the difference between getBlocks and getBlocksWithLimit? getBlocks takes a start and end slot. getBlocksWithLimit takes a start slot and a count of how many blocks to return. Use getBlocksWithLimit when you want a fixed page size rather than a fixed slot range.

Does this method return the block data? No. getBlocks returns only slot numbers. To get the actual block contents, call getBlock for each slot.

Parameters

Updated: 2026-10-19