Token Allowance Checker
Manage Token Approvals
Check and revoke token approvals to protect your wallet from unlimited spending permissions granted to smart contracts.
Token Approval Manager
Understanding Token Approvals and Security
Learn why token approvals are necessary, the risks of unlimited approvals, and how to protect your wallet.
What Are Token Approvals?
Token approvals allow smart contracts to spend your tokens on your behalf. This is necessary for DeFi interactions but creates security risks if you approve malicious or compromised contracts.
When you swap tokens on a DEX or deposit into a lending protocol, you must first 'approve' that contract to access your tokens. This is a two-step process: approve, then execute the action.
Risks of Unlimited Approvals
Unlimited approvals let contracts spend all your tokens of that type. If a contract is exploited or malicious, attackers can drain your entire balance. Always use limited approvals when possible.
Approval Management Best Practices
Use Limited Approvals: Only approve the exact amount needed for a transaction.
Regular Audits: Review and revoke unused approvals monthly.
Separate Wallets: Use different wallets for DeFi (hot wallet) and long-term holdings (cold wallet).
Common Attack Vectors
Phishing Sites: Fake DeFi interfaces that request approvals to malicious contracts.
Compromised Protocols: Even legitimate protocols can be exploited.
Malicious Airdrops: Scam tokens that request approvals when you try to sell them.
Frequently Asked Questions
Yes, each revocation is an on-chain transaction that requires gas fees. Batch revocations when gas is low, or prioritize revoking high-value token approvals first.
approve() sets a specific allowance amount, while increaseAllowance() adds to the existing approval. increaseAllowance() is safer as it prevents race conditions in approval updates.
Standard ERC20 approvals don't expire. However, some newer token standards (like ERC20Permit) support time-limited approvals. Always manually revoke old approvals for security.
Red flags: requests from unknown contracts, unlimited approvals for simple actions, approvals requested on suspicious websites, or contracts not verified on Etherscan. Always research contracts before approving.