Learn how to revoke token approvals and manage wallet permissions to protect your crypto assets from unwanted access and potential exploits.
Last Updated: February 12, 2026 at 3:20 PM UTC +1
Published: February 12, 2026 at 3:19 PM UTC +1
Human Written Content
Human Written Content
While DeFi (Decentralized Finance) and Web3 applications keep blossoming, crypto users are now interacting with more smart contracts than ever before. This means powerful new financial tools can be unlocked by this innovation, but it results in hidden risks—one of them being token approvals and wallet permissions.
Whenever you connect your wallet to a decentralized application (dApp), you are probably giving it permission to spend your tokens on it. Typically, these permissions will be live indefinitely even if you no longer use the platform. In plenty of well-publicized cryptocurrency hacks and wallets draining, the underlying issue wasn’t a hijacked private key — it was a series of unregulated token approvals.
This handbook explains what token approvals are in simple terms and their importance, how an attacker can exploit them, and—most valuable—how to get wallet permissions back safe enough for wallet over the big blockchains.
You can easily interpret that to figure out what to consider when signing tokens.
In most blockchain ecosystems, in particular Ethereum and Ethereum-like networks, tokens adhere to a standard called ERC-20. Users must expressly approve a smart contract before it can send tokens on their behalf.
When you approve a token, you’re practically saying:
‘This smart contract can move my tokens up to a set amount.’
In most instances users inadvertently authorize unlimited spending, giving the contract total access to their token balance for a lifetime.
DeFi must get approvals to operate. They allow:
Decentralized exchanges (DEXs), where tokens are swapped for currency
Lending protocols to lock collateral
NFT marketplaces to transfer assets
Yield farms to stake tokens
Smart contracts would have no interaction with your wallet’s tokens without approvals.
As you can guess, they need approvals, but you just have to wait for them. After being approved these do not sunset and are still in effect until revoked manually—if:
You stop using the dApp
The project shuts down
The ownership of the website changes hands
The contract is later exploited
This persistence is where the threat lies.
A lot of wallet drains happen in this sequence:
A user connects their wallet to a dApp.
The dApp requests unlimited token approval.
The user approves without looking at the details.
Weeks or months later, the smart contract is attacked or modified for malicious purposes.
Tokens are transferred out automatically.
The attacker never needs to know the user’s private keys.
Malicious contracts are often disguised by attackers as:
“Claim rewards” pages
NFT mint sites
Token migration tools
If approved, the contract can drain funds quietly.
Hardware wallets protect private keys, although they cannot prevent abuse of approval. If you approve a malicious contract on a hardware wallet, the contract still has permission to spend your tokens.
Security is not just about storage – it's about permissions.
Revoking unused approvals:
Reduces attack surface
Protects against future exploits
Limits damage from compromised contracts
Improves overall wallet hygiene
Think of approvals like open tabs – the more you leave open, the greater the risk.
Before revoking approvals, you will need:
Your wallet (MetaMask, Trust Wallet, Coinbase Wallet, etc.)
A small amount of native gas tokens (ETH, BNB, MATIC, etc.)
A reputable token approval checker
Widely used tools include:
Etherscan Token Approval Checker
Chain-specific explorers (BscScan, PolygonScan, Arbiscan)
These tools do not require private keys—only wallet connection.
Open the approval checker
Click “Connect Wallet”
Approve the connection in your wallet
This connection allows the tool to read your approvals, not move funds.
You’ll see a list of:
Tokens
Approved contracts
Allowance amount (limited or unlimited)
Pay close attention to:
Old DeFi platforms you no longer use
Unknown contract names
Unlimited approvals
Click “Revoke” next to the approval
Confirm the transaction in your wallet
Pay a small gas fee
Once confirmed, the smart contract can no longer access your tokens.
Use Etherscan’s Token Approval Checker or Revoke.cash
Gas fees fluctuate; consider revoking during low-fee periods
Use BscScan Token Approvals
Fees are low, making regular cleanup easy
Use PolygonScan or Revoke.cash
Especially important due to frequent DeFi usage
Use Arbiscan or Optimistic Etherscan
L2 fees are cheaper, encouraging frequent checks
NFTs also require approvals—often granting marketplaces permission to transfer all NFTs in a collection.
A compromised marketplace approval can result in:
Entire NFT collections being stolen
No additional signatures required
Use Revoke.cash or explorer NFT approval tools
Look for “ApprovalForAll” permissions
Revoke any marketplace you don’t actively use
Does not show all approvals natively
Requires third-party tools
Always review approval pop ups carefully
Limited built-in approval visibility
External tools recommended
Clear transaction previews, but approvals still persist
Manual revocation still required
Some dApps allow custom approval limits. Choose an exact amount instead of unlimited.
For new or untrusted platforms:
Create a separate wallet
Fund it with only what you need
Keep main holdings isolated
Make it a habit to:
Review approvals monthly
Revoke after large DeFi sessions
Clean up after NFT mints
Avoid google ads and fake sites
Always access approval tools through verified sources
Even one interaction – like claiming an NFT or airdrop – can create approvals.
Disconnecting only removes site access – not token permissions.
Cold wallets can still be drained via approvals if they interact with malicious contracts.
If a malicious contract already exploited an approval:
Revoke immediately
Move remaining funds to a new wallet
Consider the old wallet compromised
In severe cases, full wallet migration is the safest option.
Wallet developers and blockchain communities are working on:
Approval expiration standards
Better transaction previews
Native permission dashboards
Account abstraction safety features
Until then, user awareness remains the strongest defense.
Token approvals are powerful – and dangerous when ignored. They are not inherently bad, but unmanaged permissions create long-term security risks that many users don't realize until it's too late.
By understanding how approvals work, regularly revoking unused permissions, and practicing cautious wallet habits, you can dramatically reduce your exposure to scams, exploits, and wallet drains.
In crypto, security isn't just about protecting your keys – it's about controlling who has permission to use them.
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