Approve
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In Brief
Approving (token approval) is granting a smart contract or dApp permission to spend a specific token from your wallet. It's required to interact with DeFi and DEXs, but over-broad approvals can be a security risk.
What Is a Token Approval (Approve)?
In crypto, "approve" refers to granting a smart contract or decentralized app (dApp) permission to spend a specific token from your wallet on your behalf. Before a DEX can swap your tokens or a DeFi protocol can use them, you must first sign an approval transaction authorizing it.
Approvals are a normal, necessary part of using DeFi — but because they grant spending permission, understanding and managing them is an important part of wallet security.
How Does Token Approval Work?
You initiate an action that needs to move your tokens (e.g. a swap on a DEX).
The dApp requests approval to spend that token.
You sign an approval transaction, setting how much the contract can spend.
The contract can now move up to the approved amount when you transact.
The approval remains active until you change or revoke it.
Limited vs Unlimited Approvals
| Type | Description | Risk |
|---|---|---|
| Limited approval | Authorizes a specific amount | Lower — capped exposure |
| Unlimited approval | Authorizes any amount, indefinitely | Higher — convenient but riskier |
Many dApps request unlimited approvals for convenience, but this means the contract can spend that token freely until you revoke it — so it's worth understanding what you're signing.
Why Approvals Matter for Security
If a contract you've approved turns out to be malicious or gets exploited, an active (especially unlimited) approval could be used to drain that token. This is why security-conscious users prefer limited approvals where possible and periodically revoke approvals they no longer need.
Best Practices
Prefer limited approvals over unlimited when the option exists.
Only approve contracts and dApps you trust.
Revoke approvals you no longer use.
Read what each approval request actually authorizes before signing.
Approvals and Trust Wallet
Trust Wallet lets you interact with DeFi protocols and DEXs through its dApp browser and WalletConnect, where you'll review and sign token approvals before transacting. As a non-custodial wallet across 100+ blockchains, you stay in control of what you authorize — so approve only trusted contracts, prefer limited amounts when you can, and revoke approvals you no longer need to keep your funds safe.