Crypto Safety Tips › How to Revoke Token Approvals
The short answer: Token approvals give smart contracts permission to move your tokens or NFTs. Old or unlimited approvals are open doors if a contract is ever exploited. Check them every month or two with a token approval checker on a block explorer or a tool like revoke.cash, and revoke any you no longer use. Revoking costs a small gas fee.
What is a token approval?
When you trade on a marketplace or exchange, you usually approve its contract to move a specific token or NFT for you. That permission stays in place after you leave, often with no limit, until you remove it.
Why do old approvals matter?
If a contract you once approved is hacked, or was malicious all along, it can use your old permission to take your assets, even months later. Unlimited allowances and SetApprovalForAll are the riskiest.
How do I check and revoke them?
- Open a token approval checker on your chain's block explorer, or a tool like revoke.cash. Bookmark the real site; fake revoke sites exist.
- Enter your wallet address, or connect the wallet you want to check.
- Revoke approvals for apps you no longer use, anything you don't recognise, and any unlimited allowance you don't need.
- Confirm each revoke in your wallet. Each one costs a small gas fee.
How often should I do this?
Every month or two, and straight away if you think you signed something dodgy. Using a separate wallet for mints and games keeps the risky approvals away from your savings in the first place.
Quick questions
Does revoking cost money?
Yes, a small gas fee per revoke, because it is an on-chain transaction.
Will revoking cancel my NFT listings?
It can. If you revoke a marketplace approval, listings on that marketplace may stop working until you approve it again.
On the Scam or Safe? quiz, one card asks what a monthly approvals check is worth. Now you know.
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General safety information, not financial or legal advice. HooTang Clan has no token, and nothing on this page is a reason to buy anything. Report fraud to Action Fraud, or Police Scotland on 101.