Practical guide
Unlimited vs Exact-Amount Approvals
An ERC-20 approval can authorize a contract to move an exact amount or an effectively unlimited one. The two carry very different risk if the approved contract is later compromised.
Why unlimited approvals exist
An unlimited allowance avoids asking for a new approval on every trade, which is convenient but leaves that much of a token exposed to the approved contract indefinitely.
Exact-amount approvals limit exposure
An approval scoped to a specific trade limits what the contract can ever move to that amount, at the cost of a new approval transaction for the next trade.
Check what a swap is requesting
Before approving, check whether the amount requested matches the trade you intend to make rather than assuming it is scoped correctly.
Explore the relevant apps
Uniswap
Real swaps on Ethereum and Base, quoted on-chain and approved exactly.
ETH Hub
Revoke live token approvals, bridge to nine chains, read Ethereum and Base.
See the full Token Approval Tools workflow.