What is an unlimited token approval?
Guide · 13 September 2026
When you use a decentralized app, you usually sign an approval: a transaction that lets a smart contract move a token from your wallet on your behalf. Many apps ask for an unlimited approval — the maximum number the token supports — so you don't have to approve again later.
Why unlimited approvals are convenient — and risky
An unlimited approval is permanent until you revoke it. If the contract is later exploited, or is itself malicious, it can move the full balance of that token from your wallet at any time, without asking you again. You keep your keys, but you have already granted standing permission.
How to tell if you have one
On-chain, an approval is a call to approve(spender, amount). If amount is the maximum value (a 256-bit number), the allowance is unlimited. Block explorers and security tools can show this for a given wallet and token.
How to reduce the risk
- Revoke allowances you no longer need — especially to apps you stopped using.
- Prefer approvals for a specific amount when a dapp allows it.
- Watch for new approvals: an attacker who gains access to your wallet's signing can grant a fresh unlimited allowance.
- Keep a separate "hot" wallet for experimenting, and a cold wallet for savings.
How Shingan helps
Shingan watches for approve and ApprovalForAll events on your connected wallets across six EVM chains. When a new unlimited approval appears — especially to an unknown or flagged spender — it alerts you on Telegram and gives you a one-tap revoke link you sign yourself. Shingan never holds your keys.