How to Revoke Smart Contract Allowances (Stay Safe)
Protect your crypto by removing dangerous token approvals. Essential security for every DeFi user.
Why This Matters
Over $2 billion has been stolen through exploited token approvals. If you have ever used a DEX, bridge, or DeFi protocol, you likely have active approvals that could put your funds at risk.
What Are Token Allowances?
When you interact with DeFi protocols, you must grant them permission to move your tokens. This permission is called an allowance or approval.
How It Works
- 1You want to swap USDC for ETH on Uniswap
- 2Uniswap asks for approval to access your USDC
- 3You sign an approval transaction
- 4Uniswap can now move your USDC for swaps
The Problem
Most protocols request UNLIMITED approvals for convenience. This means:
- The contract can drain ALL your tokens
- Approval persists forever until revoked
- If hacked, attackers get full access
- Most users forget about old approvals
Why Unlimited Allowances Are Dangerous
Not all approvals carry the same risk. Here is how to assess your exposure.
Unlimited Approval
Contract can spend infinite tokens
Large Amount Approval
High value approval to less-known contracts
Old Unused Approval
Approval to contracts you no longer use
Trusted Protocol Approval
Limited approval to verified protocols
How to Check Your Allowances
Use these trusted tools to view and manage your token approvals.
Revoke.cash
100+ chains
- Free to use
- Multi-chain support
- Batch revocations
- Browser extension
Etherscan Token Approval
Ethereum + L2s chains
- Official tool
- Detailed history
- ERC-20/721/1155
- Transaction details
Step-by-Step Revocation Guide
Choose your preferred tool and follow the steps to revoke dangerous approvals.
Visit Revoke.cash
Go to the official website
- Navigate to revoke.cash in your browser
- Ensure you are on the official site (check URL)
- The site works without connecting wallet initially
Connect Your Wallet
Link MetaMask or other wallet
- Click "Connect Wallet" button
- Select your wallet provider (MetaMask, WalletConnect, etc.)
- Approve the connection request
Select Network
Choose the blockchain to check
- Click the network selector dropdown
- Choose Ethereum, Polygon, Arbitrum, or other chain
- Repeat for each network you have used
Review Allowances
Check all active approvals
- Wait for the page to load all approvals
- Sort by value at risk or date
- Identify unlimited or suspicious approvals
Revoke Unwanted Approvals
Remove risky permissions
- Click "Revoke" next to each unwanted approval
- Confirm the transaction in your wallet
- Pay the gas fee to complete revocation
Verify Revocation
Confirm approval is removed
- Wait for transaction confirmation
- Refresh the page to verify removal
- The approval should no longer appear in the list
Gas Costs Explained
Revoking approvals costs gas. Here are estimated costs per network.
Ethereum
$2-15
1-5 min
Polygon
$0.01-0.05
< 30 sec
Arbitrum
$0.10-0.50
< 1 min
Optimism
$0.05-0.30
< 1 min
BSC
$0.05-0.20
< 30 sec
Base
$0.01-0.10
< 1 min
Pro Tip: Save on Gas
Revoke approvals during weekends or early morning UTC when gas prices are typically 30-50% lower. Use gas trackers like Etherscan Gas Tracker to find the best times.
When to Revoke Allowances
Know when to take action to protect your assets.
After using a new DeFi protocol
New protocols carry higher risk of exploits
When you stop using a protocol
No need to maintain exposure to unused contracts
After interacting with NFT mints
NFT contracts often request broad approvals
Monthly security audit
Regular maintenance prevents forgotten risks
After news of protocol hack
Immediate action needed if you used the protocol
Before large token transfers
Clean slate before moving significant funds
Best Practices for Token Approvals
Follow these guidelines to minimize your risk exposure.
Use Exact Amounts
Only approve the exact amount needed for a transaction, not unlimited.
Check Before Signing
Always read approval requests carefully. Use wallets like Rabby that show risk warnings.
Regular Audits
Check your approvals monthly. Set a calendar reminder for regular reviews.
Use Separate Wallets
Keep main holdings in a cold wallet. Use hot wallets for DeFi with limited funds.
Verify Contracts
Only interact with verified contracts. Check if the contract is audited.
Revoke After Use
Immediately revoke approvals after finishing with a protocol, especially new ones.
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Get 20% OFF on BinanceFrequently Asked Questions
Common questions about token allowances and revocation.