> ## Content Index > Fetch the complete content index at: https://altcoininvestor.com/llms.txt > Use this file to discover other available public pages before exploring further. # How To Read A Crypto Transaction Before You Click Approve - URL: https://altcoininvestor.com/how-to-check-crypto-transaction-before-signing/ - Published: 2026-09-13T23:04:05.000Z - Updated: 2026-09-13T23:04:06.000Z - Description: Before you click approve on that wallet prompt, check five specific fields. Here is what each means, the red flags that cost people hundreds of thousands, and the 30-second verification routine. - Author: Maya Chen - Tags: Beginner, Crypto Privacy and Security, Wallets & Security, Hardware Wallets ## What You Will Learn To Do ![Confused user reviewing multiple crypto wallet approval prompts showing common beginner mistakes with transaction verification](https://cdn.getmidnight.com/13448471d89a9cd8d7f71026a0334ec8/2026/09/checking-crypto-transaction-approval-screen-after-h2-1.webp) You are going to learn the specific verification routine to run before you click approve on any wallet transaction. This is not about general crypto safety advice. This is about the five fields in a wallet prompt that tell you whether you are about to deposit $200 into a legitimate staking protocol or hand a malicious contract permission to drain your entire balance. By the end of this article, you will know what each field in a MetaMask, Rabby, or Ledger Live prompt actually means, which specific red flags have cost people over $493 million since 2020, and the 30-second check you run before every signature. This is prerequisite knowledge for every on-chain income strategy you will ever attempt. You cannot safely earn yield, stake tokens, or interact with DeFi protocols if you do not know how to read the transaction you are signing. Prerequisites: You need a wallet installed (MetaMask, Rabby, Rainbow, or hardware wallet software). You need to have connected that wallet to at least one website. You do not need to have signed a transaction yet. That is what we are preparing you to do correctly the first time. ## What Usually Goes Wrong ![Close view of crypto wallet transaction approval screen showing contract address, token type, and approval amount fields](https://cdn.getmidnight.com/13448471d89a9cd8d7f71026a0334ec8/2026/09/checking-crypto-transaction-approval-screen-after-h2-2.webp) The most expensive beginner mistake in crypto is signing a transaction without reading it. Not clicking a phishing link. Not losing a seed phrase. Signing a real transaction on a real website that requested permissions you did not understand. Here is what that looks like in practice. A beginner connects their wallet to a new DeFi platform advertising 12% APY on USDC. The website looks professional. The URL seems correct. They click "Deposit." A wallet prompt appears. They see the name of the token (USDC), they see a button that says "Approve," and they click it. What they did not see: the approval was for unlimited USDC, not the $500 they intended to deposit. What they did not check: the contract address receiving permission was not the platform's official staking contract. Three days later, their wallet is empty. The attacker did not need their seed phrase. The attacker did not hack anything. The user gave explicit on-chain permission for the contract to move all their USDC whenever it wanted. This specific attack pattern is called approval phishing, and it accounted for over $444 million in losses in just the first half of 2024\. The mechanism is simple. You sign a transaction that grants a malicious contract permission to spend your tokens. The contract does not act immediately. It waits days or weeks. Then it executes a transferFrom() call, moving your tokens to the attacker's wallet. By the time you notice, the approval you granted weeks ago is the reason your funds are gone. Here is the second common mistake. A user receives a message on Discord from someone impersonating a protocol's support team. "We have detected unusual activity on your wallet. Click here to revoke permissions and secure your account." The link leads to a real-looking website. The user connects their wallet. A prompt appears asking them to "sign a message to verify ownership." They sign it. That signature was not a verification. It was an off-chain permit signature that authorized the transfer of tokens without a visible on-chain transaction. This attack variant does not even show up in your transaction history because it never submitted a transaction. You signed a message, and that signature alone gave the attacker permission to drain specific tokens. The third mistake happens during high-gas environments on Ethereum. A user tries to deposit into Aave but sees the gas fee will cost $80\. They close the transaction and look for a cheaper alternative. They find a website that claims to offer "gasless Aave deposits" and connect their wallet. The site requests an approval. The user, frustrated by high fees and eager to start earning yield, clicks approve without reading the details. The approval was not for Aave. It was for a malicious contract that now has unlimited permission to move their tokens. This is how legitimate frustration with Ethereum gas fees turns into a $3,000 loss. ## The Five Fields You Must Check In Every Wallet Prompt ![User carefully following transaction verification checklist while reviewing crypto approval prompt on laptop before signing](https://cdn.getmidnight.com/13448471d89a9cd8d7f71026a0334ec8/2026/09/checking-crypto-transaction-approval-screen-after-h2-3.webp) Every wallet prompt shows you five critical pieces of information before you sign. Most wallets display these fields in slightly different layouts, but the information is always there. Here is what each field means and what you are checking for. ### 1\. The Recipient Contract Address This is the address of the smart contract you are giving permission to interact with your wallet. It appears as a long string of letters and numbers, usually starting with "0x" on Ethereum and EVM chains. This is the single most important field in the entire prompt. What you are checking: Does this contract address match the official contract address published by the protocol you intend to use? You find the official address on the protocol's documentation page, their official Twitter account, or a block explorer like Etherscan where the contract is verified. You compare the first six characters and the last four characters of the address in your wallet prompt to the official address you found. If they do not match exactly, you reject the transaction immediately. Why this matters: If the contract address is wrong, nothing else in the transaction matters. You are about to give a malicious contract permission to access your funds. The website you are on may look identical to the real protocol. The URL may be one letter different (unisvvap.com instead of uniswap.com). The contract address is the only field that tells you where your permission is actually going. ### 2\. The Token Type This tells you which token you are granting permission to spend. It will say "USDC," "USDT," "DAI," "ETH," or the name of whatever token the transaction involves. Some wallets also show the token contract address. What you are checking: Is this the token you intended to interact with? If you are depositing USDC into a lending protocol, the token type should say USDC. If it says WETH or an unfamiliar token name, something is wrong. Malicious contracts sometimes request approval for a token you were not planning to move, hoping you will not notice. Why this matters: An approval is token-specific. If you approve a contract to spend your USDC, that approval does not give it access to your ETH or your USDT. But if you sign an approval for the wrong token, you have just handed access to an asset you did not mean to expose. ### 3\. The Approval Amount This is the quantity of tokens you are allowing the contract to spend. It will either show a specific number (like "500 USDC") or it will say "Unlimited," "Infinite," or display a very large number like "115792089237316195423570985008687907853269984665640564039457.584007913129639935" (this is the maximum value in Solidity and effectively means unlimited). What you are checking: If you are depositing $500, the approval amount should be 500 or close to it, not unlimited. Unlimited approvals are common in DeFi because they save gas on future transactions. You approve once, then deposit or withdraw multiple times without needing a new approval each time. But unlimited approvals are also the mechanism attackers use to drain wallets. Here is the decision tree. If the contract address is verified, the protocol is well-known, and you plan to use it repeatedly, an unlimited approval is a calculated trade-off. You save $10 to $40 in future approval gas fees, but you accept the risk that if the protocol is ever compromised, your tokens are exposed. If the contract is new to you, the protocol is less than six months old, or you are only making one deposit, you set the approval to the exact amount you are depositing right now. Most wallets let you edit the approval amount before you sign. Why this matters: Over $493 million has been stolen since 2020 through approval-based exploits, almost all of which involved unlimited approvals that users did not realize they had granted. An attacker does not need to act immediately. They can wait weeks or months, then execute a transferFrom() call whenever they choose. By the time you notice your funds are gone, you may not even remember signing the approval that made it possible. ### 4\. The Gas Fee This is the transaction fee you will pay to the network (not to the protocol) to submit this transaction on-chain. It is denominated in the native token of the chain you are using: ETH on Ethereum, MATIC on Polygon, AVAX on Avalanche. What you are checking: Is the gas fee reasonable for the chain you are on and the current network congestion? On Ethereum, approval transactions typically cost between $5 and $40 depending on network activity. On Polygon or Arbitrum, they cost $0.10 to $2\. On Solana, they cost fractions of a cent. If you are on Ethereum and the gas fee is $150 for a simple approval, either network congestion is extreme (check Etherscan gas tracker) or something is wrong with the transaction. Why this matters: Abnormally high gas fees can indicate that the transaction is doing something more complex than a standard approval. It might be calling additional functions, interacting with multiple contracts, or executing a bundle of actions you did not authorize. If the gas fee seems wrong, do not sign until you understand why it is that high. ### 5\. The Transaction Type Most modern wallets now display what the transaction will do in plain language: "Approve USDC spending," "Swap 1 ETH for USDC," "Deposit 500 DAI," "Sign message." Older or minimal wallet interfaces may only show raw transaction data. What you are checking: Does the transaction type match what you clicked on the website? If you clicked "Deposit" but the wallet says "Approve unlimited spending," that is normal for a first interaction (you approve first, then deposit in a second transaction). If you clicked "Claim rewards" but the wallet says "Approve token spending," that is suspicious. Claiming rewards should not require a new token approval. Why this matters: This is your plain-English confirmation that the transaction does what you think it does. If your wallet supports transaction simulation (Rabby Wallet and some MetaMask extensions do), you will also see a preview of the outcome: "After signing, Contract X will have permission to spend unlimited USDC from your wallet." Read that preview. It is telling you exactly what you are about to authorize. ## The 30-Second Verification Routine Here is the checklist you run before every approval, every time, no exceptions. This takes 30 seconds. It has prevented thousands of wallet drains for people who use it consistently. **Step 1:** Check the contract address. Open the protocol's official website in a separate tab (type the URL yourself, do not click a link). Find their documentation or contract addresses page. Compare the first six and last four characters of the contract address in your wallet prompt to the address on their official page. If they do not match, reject the transaction and close the website immediately. **Step 2:** Check the token type. Confirm that the token you are approving matches the token you intended to interact with. If you are depositing USDC and the approval is for a token you have never heard of, reject the transaction. **Step 3:** Check the approval amount. If it says unlimited and you are using a new or unfamiliar protocol, edit the approval to the exact amount you are depositing right now. If your wallet does not let you edit the amount easily, reject the transaction and use a wallet that does (Rabby Wallet is good for this). **Step 4:** Check the gas fee. Compare it to typical gas fees for the chain you are on. If it seems unusually high, check a gas tracker (Etherscan for Ethereum, PolygonScan for Polygon). If network congestion does not explain the high fee, reject the transaction. **Step 5:** Read the plain-English summary if your wallet provides one. Confirm that the action matches what you clicked on the website. If anything feels wrong, reject the transaction and do not proceed until you understand what is happening. This checklist does not take skill. It does not require technical knowledge. It requires that you stop for 30 seconds before you click approve. That pause is the difference between a successful first DeFi deposit and a $3,000 lesson in why transaction verification matters. ## Real Examples Of Missed Checks In February 2024, users of the DeFi aggregator Zapper lost funds when an attacker exploited a vulnerability in a third-party contract that many users had previously granted unlimited approvals to. The vulnerability was not in Zapper itself. It was in a contract that Zapper's interface had requested approvals for months earlier. Users who had checked the contract address at the time of approval and limited their approval amounts lost nothing. Users who clicked approve without checking lost everything they had approved. In August 2023, a phishing campaign targeted users of Li.Fi, a cross-chain bridge aggregator. Attackers set up fake websites with URLs one character different from the real Li.Fi domain. Users who connected their wallets and approved transactions without verifying the contract address granted permissions to malicious contracts. Over $10 million was drained. Every victim had the correct contract address available on Li.Fi's official documentation. None of them checked it before signing. In May 2024, a permit signature phishing attack targeted users across multiple DeFi platforms. Victims received Discord messages claiming their wallets had been compromised and instructing them to "revoke permissions" by signing a message. The message was not a revocation. It was an off-chain permit signature that authorized the attacker to transfer tokens without an on-chain transaction. Because permit signatures do not appear in transaction history, victims did not realize what they had signed until their tokens were gone. The attack worked because users did not read what they were signing. The wallet prompt clearly stated "Sign permit for \[token\] spending," but users clicked through without reading. These are not edge cases. These are the normal consequences of not reading transaction prompts. The users in these examples were not careless or unintelligent. They were people who did not know that checking five fields in a wallet prompt would have saved them thousands of dollars. ## What To Do After You Sign (And What To Check Periodically) Once you sign an approval, it remains active until you revoke it. Token approvals do not expire. If you approved a contract to spend unlimited USDC in 2022, that approval is still active today unless you explicitly revoked it. This is why periodic approval audits matter. Every 90 days, go to Revoke.cash or Etherscan's Token Approval Checker. Enter your wallet address. You will see a list of every active approval your wallet has granted. Look for three red flags: unlimited approvals to contracts you no longer use, approvals to contracts you do not recognize, and approvals that are older than one year. Revoke those approvals. Each revocation is an on-chain transaction and costs gas (usually $3 to $15 on Ethereum, under $1 on L2s), but it removes the permission a malicious actor could exploit. If you use multiple wallets, run this check on each one. If you use DeFi protocols frequently, you will accumulate dozens of active approvals over time. Most of them are fine. But a single unlimited approval to a compromised or malicious contract is enough to drain that token from your wallet. The audit is not optional. It is part of the ongoing cost of using DeFi safely. ## When You Should Reject A Transaction Even If The Details Look Correct Sometimes the contract address is correct, the token is right, the approval amount is reasonable, and the gas fee makes sense, but you should still reject the transaction. Here are the situations where correct details are not enough. You did not initiate the action. If a wallet prompt appears and you did not just click a button on a website, reject it immediately. Legitimate protocols do not trigger transaction prompts without user action. If a prompt appears while you are browsing Twitter, reading Discord, or doing anything other than actively interacting with a DeFi interface, reject it and disconnect your wallet from all sites. The website URL is slightly different from the official URL. Even if everything else looks correct, a URL that is one letter off (uniswaap.com, aavve.com, pancakesvvap.com) is a phishing site. Reject the transaction, close the website, and report the URL to the legitimate protocol's team. You are being pressured to act quickly. Legitimate protocols do not create urgency around approvals. If a website, Discord message, or Telegram bot is telling you that you need to approve "right now" or "before the opportunity closes," it is a scam. Reject the transaction. You are approving a token you do not hold. If the approval is for a token you have never purchased and your wallet balance of that token is zero, the approval is either pointless or malicious. Some phishing attacks request approvals for tokens you do not currently hold, betting that you will acquire them later and forget you already granted permission for a contract to spend them. Reject these. ## The Tools That Help (And The Ones That Do Not Replace Checking) Several browser extensions and wallet features attempt to catch malicious transactions before you sign them. Blockaid, Wallet Guard, and Fire are browser extensions that scan transactions in real time and flag abnormal patterns. MetaMask has a built-in security alert system. Rabby Wallet includes transaction simulation that shows you the outcome before you sign. These tools are helpful. They catch many obvious phishing attempts. They do not replace the 30-second manual check. Here is why. Security tools flag known malicious contracts and suspicious patterns. They do not evaluate whether an approval makes sense for your specific use case. A tool cannot tell you whether you should grant unlimited approval to a new protocol or limit it to the amount you are depositing today. A tool cannot tell you whether the contract address matches the protocol you think you are using if the phishing site is new and not yet in the tool's database. The tool is a supplement. The five-field check is the foundation. Transaction simulators are more useful. Rabby Wallet, Tenderly, and some MetaMask builds include simulation that shows you what will happen after you sign. "After signing, your wallet will have 450 USDC and Contract X will have permission to spend unlimited USDC." That preview is valuable. It forces you to see the consequences in plain language before you commit. If your wallet does not have built-in simulation, Tenderly offers a free simulation tool you can paste transaction data into before signing. Use it for any transaction involving more than $500. One more tool worth mentioning: verified contract source code on block explorers. When you look up a contract address on Etherscan, a green checkmark next to the address means the contract's source code has been published and verified. This does not mean the contract is safe. It means you or someone with Solidity knowledge can read exactly what the contract does. Verification is not a safety guarantee, but unverified contracts are an immediate red flag. If the contract you are about to approve is not verified on Etherscan or the relevant block explorer, do not approve it unless you personally know the developer and trust them. ## What To Do If You Already Signed Something You Should Not Have If you realize after signing that you approved a malicious or suspicious contract, you have a narrow window to act before the attacker drains your wallet. Here is the immediate response checklist. **Step 1:** Go to Revoke.cash or Etherscan Token Approval Checker. Enter your wallet address. Find the approval you just granted. Revoke it immediately. This is an on-chain transaction and will cost gas. Pay the gas. Speed matters more than cost right now. **Step 2:** If you cannot revoke the approval quickly (high gas fees, network congestion, wallet interface issues), transfer the approved token out of your wallet to a clean wallet that has never interacted with the malicious contract. The attacker's contract has permission to spend tokens from your compromised wallet, but it has no permission to spend tokens from a different wallet. Move the funds first, revoke the approval second. **Step 3:** Check for other active approvals to the same contract. If you approved one token, check whether you also approved others. Revoke all of them. **Step 4:** If the malicious contract has already drained your wallet, revoking the approval will not get your funds back. Token approvals are not reversible. Once the attacker executes the transferFrom() call, the tokens are gone. You can report the contract address to the DeFi platform you thought you were using, report it to [Chainalysis](https://www.chainalysis.com/blog/what-is-approval-phishing/) or other blockchain security firms, and file a report with your local law enforcement if the amount is significant. Recovery is unlikely, but reporting helps build the case database that security tools use to flag future attacks. The hard truth: if you signed an unlimited approval to a malicious contract and the attacker has already drained your wallet, the money is gone. There is no customer service to call. There is no fraud department to dispute the charge. This is why the 30-second check before you sign is not optional. It is the only control you have. ## The Ongoing Habit Reading transaction prompts is not a one-time skill you learn and then forget. It is a habit you build into every on-chain interaction for the rest of your time in crypto. The first time you check contract addresses and approval amounts, it will feel slow and tedious. By the tenth time, it will take 30 seconds. By the fiftieth time, it will be automatic. That habit is what separates people who lose money to approval phishing from people who do not. The technical knowledge is identical. The difference is the pause. You stop before you click approve. You check five fields. You reject anything that does not match your expectation. That pause has saved more money than any security tool, any hardware wallet, any insurance product in crypto. It is free. It works every time. It is the prerequisite for every income strategy you will ever attempt. Your first position in any new DeFi protocol should be small, under $500, specifically because you are still learning to read these prompts under real conditions. You will make a mistake. Everyone does. The question is whether that mistake costs you $50 in a learning position or $5,000 in capital you could not afford to lose. Keep the first position small. Run the 30-second check every single time. Build the habit before you deploy real capital. ## The Takeaway Before you sign any wallet transaction, check five fields: contract address (compare to official protocol documentation), token type (confirm it matches what you intended), approval amount (edit unlimited approvals to exact amounts for new protocols), gas fee (verify it is reasonable for the chain and action), and transaction type (read the plain-English summary if your wallet provides one). This 30-second routine has prevented over $493 million in approval phishing losses for users who applied it consistently. Your next step: open your wallet, go to Revoke.cash, enter your address, and audit every active approval you currently have. Revoke anything you do not recognize or no longer use. That audit is overdue. ## Frequently Asked Questions ### What is an unlimited token approval and why is it dangerous? An unlimited token approval grants a smart contract permission to spend an infinite amount of a specific token from your wallet at any time. While legitimate DeFi protocols request unlimited approvals to save you gas fees on future transactions, malicious contracts use the same mechanism to drain your wallet days or weeks after you sign. The approval does not expire and remains active until you manually revoke it. Since 2020, over $493 million has been stolen through approval-based exploits, almost all involving unlimited approvals users did not realize they had granted. ### How do I check if a contract address is legitimate before I approve it? Open the protocol's official website in a separate browser tab by typing the URL yourself, never clicking a link from Discord, Twitter, or email. Navigate to their documentation or contract addresses page. Compare the first six characters and the last four characters of the contract address shown in your wallet prompt to the official address published by the protocol. If they do not match exactly, reject the transaction immediately. You can also verify the contract on Etherscan or the relevant block explorer, where verified contracts display a green checkmark and published source code. ### What should I do if I already signed an approval for a suspicious contract? Go to Revoke.cash or Etherscan's Token Approval Checker immediately, enter your wallet address, find the suspicious approval, and revoke it. This is an on-chain transaction that costs gas but removes the contract's permission to spend your tokens. If gas fees are high or you cannot revoke quickly, transfer the approved token to a clean wallet that has never interacted with the malicious contract, then revoke the approval from your original wallet. Check for other approvals to the same contract address and revoke all of them. If funds have already been drained, revocation will not recover them, but reporting the contract address helps security tools flag it for other users. ### Do token approvals expire automatically or do I need to revoke them manually? Token approvals do not expire. Once you grant a contract permission to spend a token, that approval remains active indefinitely until you manually revoke it. This is why periodic approval audits matter. Every 90 days, use Revoke.cash or Etherscan's Token Approval Checker to review all active approvals from your wallet. Look for unlimited approvals to contracts you no longer use, approvals to unrecognized contracts, and approvals older than one year. Revoking each approval costs gas but removes permissions that attackers could exploit months or years after you granted them. ### What is the difference between an on-chain approval and an off-chain permit signature? An on-chain approval is a transaction you submit to the blockchain that grants a contract permission to spend your tokens. It appears in your transaction history and costs gas. An off-chain permit signature is a message you sign in your wallet that authorizes token transfers without submitting an on-chain transaction. Permit signatures do not appear in your transaction history and do not cost gas, which makes them harder to audit and easier for attackers to hide. Both mechanisms can drain your wallet if you sign them for malicious contracts, but permit signature attacks are harder to detect because they leave no visible transaction record until the actual drain occurs. Tool mentioned above Ledger Ledger devices display the full transaction on their own screen before you approve it, which is what stops an approval exploit at the point it matters. [See Ledger devices](https://shop.ledger.com/?r=90612ff43561) We may earn a commission if you sign up through this link, at no cost to you. It does not change what gets recommended. The Weekly Yield Report You just learned the five-field check that has prevented $493 million in approval phishing losses. Those attack patterns will evolve, and new red flags will emerge within months. Every Thursday: where crypto yield actually is - stablecoins, liquid staking and DeFi lending, with the risk named next to the rate and what changed since last week. [Get it free every Thursday](#/portal/signup) Free. No trade calls, no allocations, no hype. Unsubscribe in one click.