5.5 First Transaction Walk-through
What you'll learn: How to send and receive stablecoins safely using a test network, so you can practice without risking real money.
Making your first blockchain transaction feels intimidating because mistakes can't be reversed. That's why we'll practice on Sepolia, Ethereum's test network, where you can learn with fake tokens that cost nothing. Once comfortable here, the same steps work on the real network.
Understanding Ethereum Transaction Components
Every stablecoin transaction on the Ethereum network consists of four things:
Recipient Address: The 42-character string starting with "0x" where funds will go. One wrong character means permanent loss.
Asset and Amount: Which stablecoin (USDC, USDT) and how much to send.
Network: For practice, we'll use Sepolia testnet. Real transactions use Ethereum Mainnet.
Gas Fee: Payment in ETH to process your transaction. Even sending stablecoins requires ETH for fees. The fee amount fluctuates based on network congestion. Crucially, you must have ETH in your wallet to pay for gas, even when you are only sending stablecoins.
Getting Started
This guide uses test tokens with no value. Perfect for learning without financial risk.
Make sure you have Metamask correctly installed as a browser extension. If you are new to the Web3 space, please follow the guide on how to set up your Metamask wallet.
Receive Stablecoins
Step 1: Open MetaMask
Launch your MetaMask browser extension.
Step 2: Select the Right Network
2.1 Open Network Menu
2.2 Select Network
Click the network dropdown at the top. For this practice, select "Sepolia Testnet". For real funds, you'd use "Ethereum Mainnet".
Step 3: Copy Your Address
Your Ethereum address appears at the top of the wallet, under your account name (e.g., "Account 1"), shortened like "0x2D216...9141d". Click to copy the full address to your clipboard. This single address receives both ETH and all ERC-20 tokens on the Ethereum network.
Step 4: Share Your Address
Send this address to whoever's sending you funds. Always copy-paste rather than typing manually to avoid errors.
Getting Test Tokens to Your Wallet
Before sending anything, you need test ETH for fees and test stablecoin to send. We'll use "faucets" - services that give free test tokens.
Copy the address you get by performing previous section Receive Stablecoins.
Sepolia ETH Faucet
1. Open a Faucet
For topping up Sepolia ETH we will use GoogleCloud Web3 Faucet. There are other providers that have Faucets as well.
Go to: https://cloud.google.com/application/web3/faucet/ethereum/sepolia
2. Paste your MetaMask address
3. Click to receive Tokens
This step might take a few moments in order for the transaction to confirm.
Sepolia USDC Faucet
These are going to be Testnet tokens; they are not worth anything.
Step 1: Open Faucet
For topping USDC tokens, we will use official Circle Faucet for USDC. Circle is the organisation behind USDC Stablecoin.
Go to: https://faucet.circle.com
Step 2: Select Stablecoin, Network and Insert Wallet Address
Step 3: Receive Tokens
Send Stablecoins
Step 1: Select the Stablecoin
In MetaMask's "Tokens" tab, click on the stablecoin you want to send (e.g., USDC).
1.1 Import Tokens
1.2.1 Import USDC on Ethereum Mainnet
This step is not applicable in this guide; it only shows how to import USDC on Ethereum Mainnet!
1.2.2 Import USDC on Sepolia Testnet
Insert the following Token Address: 0x1c7d4b196cb0c7b01d743fbc6116a902379c7238
Select Sepolia network and insert Token contract address; Other fields are populated automatically. This is the address of Testnet USDC token on Sepolia.
Click on "Import" to import the token
1.3 Select Imported USDC
Step 2: Start the Transfer
Click "Send" and enter the recipient's address.
Step 3: Enter Recipient's Address
In the "To" field, paste the recipient's full Ethereum address (starting with "0x"). Select any valid address or use the following for the example: 0x6135aCD33b402Ed6C45F6a701b1dD4Ef3C18B75d .
Step 4: Crucial Security Check
Manually double-check the first 4-5 and last 4-5 characters of the pasted address against the address provided by the recipient. This simple step is a powerful defense against "clipboard hijacking" malware, which can maliciously replace a copied address with a scammer's address.
Step 5: Enter the Amount
If you followed this guide, you should have at least 10 Testnet USDCs in your wallet, which you can send as you wish.
Step 6: Review and Confirm
MetaMask will display a final confirmation screen. This screen shows the recipient address, the amount being sent, and the estimated Gas Fee in ETH.
Step 7: Wait for Confirmation
The transaction will then appear as "Pending" in your "Activity" tab until it is confirmed by the network. Sepolia transactions typically confirm in 15-30 seconds. You'll see:
Transaction hash (your receipt)
Status change from "pending" to "confirmed"
Updated balance
Important Differences on Mainnet
When using real Ethereum:
Gas fees cost real money ($3-50 per transaction)
Mistakes are permanent and costly
Always send test amounts first
Network congestion affects fees and speed
Next Steps
Once comfortable with test transactions, you're ready for real ones. The process is identical, but now mistakes cost money. Start with small amounts on mainnet and gradually build confidence.
The next section covers security practices to protect your funds and solutions to common problems.
Key Takeaways:
Every Ethereum transaction requires four components: recipient address, asset/amount, network selection, and ETH for gas fees
Practice on Sepolia testnet with free tokens before risking real money on mainnet
Always verify recipient addresses by checking first and last 4-5 characters to prevent clipboard hijacking
Gas fees on mainnet cost $3-50 in real ETH, even when sending stablecoins
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