What is a transaction hash and what does it tell me?

A transaction hash (txid or tx hash) is a unique identifier for every transaction on the blockchain — a long string of letters and numbers that looks like 0x7e4d... Paste it into Etherscan to see the full details: sender, recipient, value, gas used, status, block number, and all decoded input data. It's the receipt for any blockchain action.

What does "pending" mean on Etherscan?

A pending transaction has been broadcast to the network but not yet included in a block. It's waiting in the mempool for a validator to pick it up. Transactions with insufficient gas price may stay pending indefinitely. You can speed up a stuck transaction by resubmitting it with the same nonce but a higher gas price, which replaces the pending version.

How can I tell if a transaction was a token approval or a transfer?

Look at the "Input Data" section of the transaction and click "Decode Input Data." For an ERC-20 transfer, the function will be "transfer(address, uint256)" showing the recipient and amount. For an approval, it will be "approve(address, uint256)" showing the spender address and the approved amount. If the amount is the maximum uint256 value (a very large number like 1.15792089e+77), it's an unlimited approval.

Blockchain Basics · Etherscan · Transaction Analysis

How to Read a Blockchain Transaction on Etherscan

Every transaction you've ever made is public, permanent, and readable by anyone. Once you know how to read one, you can verify exactly what happened — before you sign and after.

MetaMask shows you a transaction confirmation. You click Confirm. Later you want to know: did it go through? Where exactly did it go? What did that contract call actually do?

Etherscan (etherscan.io) records every Ethereum transaction in a public, human-readable format. Learning to read it takes ten minutes and changes how you interact with crypto permanently.

The key fields on a transaction page

•
Transaction Hash
The unique ID for this transaction. Starts with 0x. Share this with anyone who needs to verify a transaction happened.
•
Status
Success, Failed, or Pending. Failed transactions still cost gas — the fee is paid to validators even if the transaction didn't complete. A transaction can fail if it runs out of gas, hits a require() condition in the contract, or reverts for any reason.
•
From / To
From is the sender — the wallet that initiated the transaction. To is the recipient, which may be another wallet or a smart contract address. If To is a contract, click it to see what the contract is and check if it's verified.
•
Value
The amount of ETH transferred in this transaction. For token transfers or approvals, this is often 0 ETH — the token movement shows up in the "Token Transfers" section instead.
•
Transaction Fee
The total gas cost you paid. This breaks down into Gas Limit (max you were willing to spend), Gas Used (what was actually consumed), and Gas Price (the rate you paid). Multiply Gas Used by Gas Price to get the total.

Reading the Input Data section

The Input Data field shows what function was called on the contract and with what arguments. In raw form it looks like hex garbage. Click "Decode Input Data" to see it in human-readable form.

This is where you see whether a transaction was:

•A token transfer — function: transfer(address to, uint256 amount)
•An approval — function: approve(address spender, uint256 amount). Check the amount: max uint256 = unlimited approval.
•A swap — function names like exactInputSingle or swapExactTokensForTokens with multiple parameters
•An NFT mint — function: mint(address, uint256) or similar

Tracing where funds went

If you sent tokens but the recipient says they didn't receive them, check the Token Transfers section on the transaction page. This shows all ERC-20 token movements triggered by the transaction — which can be many, especially for a swap that routes through multiple pools.

For more complex transactions, click the "Internal Txns" tab. This shows ETH transfers that happened inside smart contract execution — not visible in the main transaction value, but real movements of funds.

Checking a contract before you interact

If a transaction is asking you to interact with a contract you don't recognize, paste the contract address into Etherscan before confirming:

?Is it verified? Verified contracts have their source code visible on Etherscan — unverified contracts are a yellow flag.
?How old is it? A contract deployed in the last 24 hours asking for large approvals is suspicious.
?What other transactions has it processed? If wallets are draining out, that's a drainer.
?Does the contract name or label on Etherscan match what the site is claiming?

Frequently asked questions

What is a transaction hash?

A unique identifier for every transaction — the receipt of any blockchain action. Paste it into Etherscan to see everything that happened: sender, recipient, value, gas, status, and what contract function was called.

What does "pending" mean?

Broadcast to the network but not yet included in a block. Waiting in the mempool. Transactions with too-low gas prices may stay pending. You can replace a pending transaction by resubmitting with the same nonce and a higher gas price.

How can I tell if a transaction was an approval?

Decode the Input Data on Etherscan. Approvals show the function approve(address spender, uint256 amount). If amount is a very large number, it's an unlimited approval.

Understand transactions before they're on Etherscan

GuardianAI explains every MetaMask transaction in plain English before you confirm it — so you don't need to decode hex input data to know what you're signing. Free Chrome extension.

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