Introduction
New to cryptocurrency and web3?
This guide explains the anatomy of blockchain transactions, common reasons for transaction failures, troubleshooting steps, and FAQs to help you navigate MetaMask transactions smoothly.
Anatomy of a Blockchain Transaction
In public blockchain networks, a "transaction" typically refers to an interaction between two addresses—transferring tokens or other crypto assets. Smart contract interactions ("internal transactions") are beyond this guide's scope.
How Transactions Work
- Request Initiation: A user (e.g., Guillaume) sends 0.5 ETH to another address (Dolores) via MetaMask.
- Local Mempool: The transaction enters a temporary holding state.
- Network Processing: Nodes pick up the transaction based on gas fees (higher fees = faster processing).
- Ledger Update: Nodes verify balances and adjust the distributed ledger—deducting 0.5 ETH from Guillaume’s account and crediting Dolores’s.
"Transactions are ledger requests, not physical transfers."
Key Concepts
- Gas Fees: Paid in the network’s native currency (e.g., ETH), gas compensates miners/validators. Learn more about gas settings.
- Private Key Verification: Transactions are signed using your wallet’s private key for security.
Common Transaction Failures
1. Pending Transactions
- Cause: Low gas fees during network congestion.
- Solution: Speed up or cancel the transaction via MetaMask’s activity tab.
👉 How to speed up pending transactions
2. Out-of-Gas Errors
- Cause: Insufficient gas limit for complex operations (e.g., NFT minting).
- Fix: Adjust gas limits or test transactions on a testnet first.
3. Nonce Issues
- Cause: Conflicting transactions from the same address.
- Solution: Manually set the nonce or reset your wallet.
Troubleshooting Steps
| Issue | Solution |
|---|---|
| Stuck in local mempool | Lock/unlock MetaMask. |
| Broadcasted but stalled | Use a nonce adjustment tool. |
| "Out of gas" error | Increase gas limit or retry. |
FAQs
Q: Can I send a transaction from another account in the same wallet while one is pending?
A: Yes. Nonces are account-specific, not wallet-wide.
Q: Why did my transaction fail despite having enough ETH?
A: Gas limits might be too low for the operation’s complexity.
Q: Can I reverse a confirmed transaction?
A: No. Blockchain transactions are irreversible once confirmed.
Resources
Need more help? Explore MetaMask’s support hub for detailed guides.