ERC-20 Approve Lab
Call approve() on a real token, estimate gas before signing, and verify the Approval event on-chain.
intermediateSepolia
Learning Objectives
- →Read current allowance(owner, spender) before acting
- →Simulate the call to get a gas estimate before signing
- →Sign and broadcast approve() with your wallet
- →Verify the Approval event in the transaction logs
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Connect & Switch to Sepolia
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Configure Approval
0x779877A7B0D9E8603169DdbD7836e478b4624789
View on Etherscan →Tip: use your own address to approve yourself (safe for testing).
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Gas Estimation
We simulate the call before you sign. If simulation fails, the real tx would also fail — saving you gas.
Estimated gas unitsFill in the form and connect to Sepolia
ERC-20 approve() typically costs ~46,000 gas.
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