Solana Transaction Expired: Blockhash Mechanics Explained
You click confirm. The wallet shows pending. Sixty seconds later: "transaction expired," "blockhash not found," or "block height exceeded." No swap, possibly no fee, definitely no clear explanation from the UI. This is a protocol-level behavior worth understanding properly before you hit retry. How Solana Encodes a Deadline Into Every Transaction When an application constructs a transaction, it…
When you click "confirm" on a transaction, your wallet displays "pending" for up to a minute. However, after that time, the transaction can "expire" and show an error message stating "blockhash not found" or "block height exceeded." This is a built-in design that prevents a signed transaction from being replayed at a different price.
Transactions have a 150-block deadline, which is roughly one to one-and-a-half minutes under normal conditions. If the deadline passes, all validators reject the transaction because it was received too late. This prevents the potential issue of replaying an old transaction at a new price.
Several factors can cause a transaction to miss its deadline, including network congestion, low priority fee, and RPC propagation failures. If a transaction expires, no state changes on the blockchain occur. This means no tokens are moved and no base fee is charged. This is different from a failed transaction, which was included in a block but stopped during execution and pays a base fee.
It's crucial to confirm the transaction status before retrying, as some wallets may show "pending" or "expired" even when the transaction actually settled. Always check your token balances and verify the status on a block explorer like Solscan or Solana Explorer. Only retry after confirming that nothing actually landed. To improve swap landing rates, approve wallet popups quickly, enable or increase priority fees, and re-check the quote during retries. Some apps automatically adjust fees during high-traffic periods.
Written by urgent.news from Dev.to's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
