What a Web3 wallet is, and how it differs from an exchange account
"Not your keys, not your coins" is repeated as though it settles the question. It does not — it just describes which of two failure modes you have chosen.
In one line: an exchange account is a claim against a company that can help you when you make a mistake. A wallet is a key you hold, where a mistake is final and nobody can intervene.
So the question is not which is safer. It is which failure you are better placed to survive — a platform failing, or you losing a piece of paper.
The actual difference
An exchange account is a record in a company's database. Your balance is a number they maintain and an obligation they owe you. A wallet is a key pair (ethereum.org's own introduction to wallets is a reasonable neutral starting point); the "balance" is what the blockchain says the address controls, and whoever holds the key controls it.
| Exchange account | Web3 wallet | |
|---|---|---|
| What you hold | A claim against a company | A private key |
| Forgot your password | Recoverable through support | No password to forget — but lose the phrase and it is over |
| Sent to the wrong place | Sometimes recoverable through support | Never |
| Fails when | The company fails, or restricts your account | You lose the phrase, or someone else obtains it |
| Identity required | Yes | No |
| Reaches on-chain applications | No | Yes — that is the point of it |
Read that table as a symmetry rather than a scoreboard. Custody transfers the risk to an institution and buys you a support desk. Self-custody removes the institution and removes the support desk with it. There is no row where one is simply better.
One phrase worth retiring: a wallet does not "contain" your coins. The assets are entries on a blockchain associated with an address. The wallet holds the key that can authorise changes to those entries. This is not pedantry — it is why reinstalling the app loses nothing if you have the phrase, and why having the app loses everything if you do not.
The seed phrase is the whole thing
Twelve or twenty-four words, generated once. From them, every key in the wallet is derived. Which means:
- Anyone with the phrase has the assets. Not "can request access" — has them, immediately, from anywhere, with no further step.
- Without the phrase, nobody can help. Not the wallet's developers, not an exchange, not a recovery service. There is no reset, because there is no account.
Which produces two rules with no exceptions:
Never enter it anywhere except the wallet application itself, when restoring. No website, no support agent, no verification form, no airdrop claim. There is no legitimate reason any other party needs it. A request for a seed phrase is proof of theft in progress, full stop — the request itself is the evidence, regardless of how plausible the surroundings are.
Never store it as digital text. Not a screenshot, not a note app, not cloud storage, not a password manager, not an email to yourself. Anything that syncs is a copy on someone else's computer. Write it on paper, or stamp it into metal, and store it where a fire or a burst pipe would not take it. Two copies in two places beats one perfect copy.
Token approvals: the risk nobody expects
This one catches people who have done everything else right, because it does not involve giving anything away.
To let an on-chain application move a token on your behalf, you sign an approval. Many interfaces request an unlimited allowance by default, because it means you never have to approve again. It also means that contract can move that token from your address, in any amount, at any time in the future.
The approval outlives the interaction. If the contract is later compromised — or was malicious from the start and simply waited — the allowance is still there. People are drained months after using something once, and nothing was stolen from them at the time.
Three habits:
- Set a specific allowance rather than unlimited, where the interface permits it. It is one extra approval per interaction and it bounds the exposure.
- Review and revoke old approvals periodically. A block explorer such as Etherscan provides an approval-checking view for exactly this.
- Use a separate address for anything experimental. Fund it with what that experiment is worth and nothing more. An approval granted from an address holding almost nothing costs almost nothing.
When a hardware wallet is worth it
A hardware wallet keeps the private key in a device that never exposes it to your computer. Transactions are signed on the device and you confirm on its own screen. If your computer is compromised, the key still is not.
It is worth it when the amount you are protecting exceeds the cost of the device by a comfortable margin, and you intend to hold rather than trade constantly. It is not worth it for small balances you move frequently — the friction pushes people into shortcuts that undo the benefit.
Two things it does not do. It does not protect you from approving a malicious transaction, because you approved it — read what the device screen says, which is the reason it has one. And it does not remove the seed phrase problem: the device can be replaced, the phrase cannot.
Buy from the manufacturer directly. A device that arrives with a pre-printed recovery phrase in the box is a trap, and it is a common one.
How to split between the two
Most people who use both settle into something like this, and it is a reasonable default:
- Exchange account: what you are actively trading, and fiat on its way in or out. The support desk and the recovery path have real value for money in motion, and that is the situation where you are most likely to make a fixable mistake.
- Wallet, hot: what you need for on-chain activity. Funded deliberately, treated as spending money, and not the address that holds anything you would miss.
- Wallet, hardware: longer-term holdings that do not need to move. No approvals granted from it, ideally no interaction with applications at all.
The unifying idea is that each layer holds only what its failure mode can afford to lose. It is a boring arrangement and it is why it works.
Our position on the maximalist version of "not your keys, not your coins": it is correct about the risk it names and silent about the one it creates. Self-custody moves the failure from an institution to a household, and households lose paperwork, have fires, and die without telling anyone where things are. If you are moving assets to self-custody, the plan for the phrase — where it lives, who can find it, what happens if you cannot — is not an afterthought to the decision. It is the decision.