Token approvals checker on Base
Reviewed 2026-06-25
Answer: Token approvals on Base never expire on their own. To close your risk, list every contract that holds a spending approval on your Base wallet and revoke the ones you no longer use — especially unlimited approvals to inactive or unknown contracts.
The problem on Base
Every Base protocol you ever connected to may still hold spending approval over your tokens. Old approvals accumulate silently and never expire unless you revoke them.
A scan takes less time than it takes to regret skipping it — and individual checks are always free.
Warning signs to watch for
- Unlimited approval (max uint256) to any contract
- Approvals to unverified or inactive contracts
- Many approvals you do not recognize in your wallet history
- Approvals to protocols you connected once and never returned to
Any one of these is a reason to check before acting. Several at once is a reason to stop.
What the Base scanner checks
The Base approvals scanner reads your wallet's on-chain approval history and identifies unlimited approvals, approvals to unverified contracts, and approvals to contracts no longer active. Revoking is a standard Base transaction — small gas cost, permanent fix.
How to run the Base check
- Open the scanner at https://app.web3defender.tech and select Approvals.
- Paste your Base wallet address.
- Review the active approvals list and risk flags.
- Revoke any approval you do not recognize or no longer need.
General protection habits
- Check before connecting — not after. The scan is free and read-only.
- Revoke approvals you no longer use. Unlimited idle approvals are the most common attack surface.
- Open dApps from bookmarks — never from DM links or social-media ads.
- Treat urgency as a warning sign to slow down, not speed up.
- Legitimate services never DM you first or ask you to sign anything outside the official app.
Frequently asked questions
Do Base token approvals ever expire automatically?
Standard ERC-20 approvals on Base do not expire. Only protocols that implement Permit2 or similar standards include time limits.
Is revoking a Base approval free?
Revoking costs a small amount of gas — typically under a dollar on mainnet, much less on L2 chains.
Which Base approvals are riskiest?
Unlimited approvals to unverified or inactive contracts. Also watch for approvals to bridges or aggregators you used once and forgot.