Updated Rules checked 2026-10-21
The difference between a cold wallet and a hot wallet is whether the private key is online. A hot wallet keeps its private key on an internet-connected phone, computer or server; a cold wallet (usually a hardware wallet) keeps the private key on an offline device and signs transactions inside that device. Coins sitting in an exchange account are a different case again: the exchange holds the private key, and all you have is a username and password.
Whether to move coins from an exchange to your own wallet depends on which risk worries you more. On the exchange, you face the platform getting hacked, pausing withdrawals or freezing your account. In your own wallet, once your seed phrase is lost or leaked, no customer support team can get it back for you. The part you trade often is more convenient on the exchange; only the part you hold long term is worth considering for self-custody, and only if you can keep the seed phrase safe.
Below I lay out who holds the private key for 5 types of wallet, which type the Web3 wallet inside each of 5 exchange apps belongs to (Binance, OKX, Bybit, Bitget and Gate), then the basic rules for seed phrases, the most common ways people lose coins, and the steps for withdrawing from an exchange to a wallet, along with what a test transfer costs.
Key points: (1) The exchange holds the private key for your exchange account; with a hardware wallet or a seed phrase wallet, you hold the private key yourself, and if you lose the seed phrase it cannot be recovered. (2) The Web3 wallets inside exchange apps are mostly self-custody: the official Binance Wallet FAQ states that if you forget your recovery password or lose your cloud backup and also lose your device or delete the app, Binance cannot recover the wallet for you. (3) Bybit’s Cloud Wallet (private key held by Bybit) and Keyless Wallet were shut down at 12:00 (UTC) on 2025-05-31; only the seed phrase wallet remains. (4) A BIP39 seed phrase is 12 to 24 English words; 12 words stand for a 128-bit random number, so the odds of brute-forcing it are negligible, and the real risk is you handing the seed phrase over yourself. (5) Binance’s withdrawal guide recommends a small test to any new address first; the cost of the test is one extra withdrawal fee, and the USDT fees read from official APIs on 2026-10-21 ranged from 0.01 to 5.5 USDT, depending on the exchange and network.
The information below was checked against official pages on 2026-10-21 (the fact-check date) and is provided for reference.
Cold wallet vs hot wallet: who holds the private key in 5 wallet types?
A wallet doesn’t actually hold coins; the coins are always recorded on the blockchain. What a wallet holds is the private key that can move them. So the first question when choosing a wallet is who has the private key, and whether it can be recovered if lost. For a quick definition, see hot wallet / cold wallet. The table puts 5 common wallet types side by side by custody model:
| Type | Who holds the private key | How it’s backed up | If you lose it | Main risks |
|---|---|---|---|---|
| Exchange account | The exchange | Username and password plus two-factor authentication; no seed phrase | You can go through the exchange’s reset process | Platform hacks, withdrawal pauses, account freezes |
| Web3 wallet in an exchange app | Depends on the product; most are self-custody (MPC key shares or a seed phrase) | Cloud backup plus a recovery password, or a written-down seed phrase | Binance states it cannot recover the wallet if both the backup and the device are lost | Lost backups, phishing sites, malicious approvals |
| Software wallet (mobile app, browser extension) | You, with the private key on an internet-connected device (hot wallet) | Write down the seed phrase | Without the seed phrase it cannot be recovered | Fake apps, infected devices, phishing sites |
| Hardware wallet (cold wallet) | You, with the private key inside an offline device | Write down the seed phrase: 24 words for Ledger; 12, 20 or 24 words for Trezor | Restore it on a new device with the seed phrase | Seed phrase leaks, buying a tampered device |
| Multisig wallet (e.g. Safe) | Several signers; every transaction needs the threshold number of signatures | Each signer key is backed up separately | If the threshold is lower than the total number of signers, the remaining signers can replace the lost key | More complex setup; every transaction needs several people to sign |
Sources: Binance Wallet FAQ (updated 2025-12-02), Ledger: what is a recovery phrase (updated 2026-06-19), Trezor: wallet backup, Safe: which setup should I use; checked 2026-10-21.
Exchanges split their own funds into hot and cold wallets too. Of the 13 exchanges this site covers, 7 have had platform wallets stolen from, 8 times in total. In 7 of those incidents the stolen funds came from hot wallets, warm wallets or platform wallets whose type wasn’t disclosed; only Bybit’s 2025 incident involved a cold wallet, which was tampered with during a transfer (checked by this site on 2026-10-12; details in exchange safety record). A cold wallet protects the private key by keeping it offline, but the moment you sign a transfer things can still go wrong, and the same is true of a personal hardware wallet.
Is the Web3 wallet in an exchange app held by the exchange?
Mostly not. Many people assume that anything inside an exchange app is held by the exchange, but several exchanges’ official guides describe their Web3 wallets as self-custody: you make the backup yourself, and if it’s lost the exchange can’t get it back. These are the 5 exchanges for which I found an explanation on official pages:
| Exchange wallet | Custody | Backup and recovery | Limits stated officially | Source |
|---|---|---|---|---|
| Binance Wallet | Self-custody MPC wallet with no seed phrase; it creates 3 key shares stored in different places such as the cloud and your device, and at least 2 are needed to use it | Recovery password plus an iCloud / Google Drive cloud backup | If you forget the recovery password or lose the cloud backup and also lose the device or delete the app, Binance cannot recover the wallet for you | FAQ (updated 2025-12-02), backup guide (updated 2026-02-23) |
| OKX Wallet | Self-custody; a seed phrase wallet, or a social login wallet signed in with Google, Apple or email | The seed phrase is 12, 18 or 24 English words and should be written on paper; a social login wallet’s keys are generated and managed in a Trusted Execution Environment (TEE) | If the seed phrase is lost and the wallet is deleted, the assets cannot be recovered; exporting the seed phrase from a social login wallet permanently unlinks it from the social account | Seed phrase guide (updated 2026-08-04), social login FAQ (updated 2026-09-15) |
| Bybit Wallet | Only the seed phrase wallet remains; the user has full control of the seed phrase and private key | Write down the seed phrase | Cloud Wallet (private key held by Bybit) and Keyless Wallet were shut down at 12:00 (UTC) on 2025-05-31 | Differences between the 3 wallets (updated 2025-10-20), discontinuation FAQ (updated 2025-11-25) |
| Bitget Wallet | A separate wallet app; offers a seed phrase wallet and a keyless MPC wallet | A 12- or 24-word seed phrase; the MPC wallet is backed up to iCloud or Google Drive | A lost or stolen seed phrase may lead to loss of assets | Bitget Wallet Academy (2024-01-02) |
| Gate Wallet | A self-custody multichain Web3 wallet, created in the Web3 section of the Gate app | Can be created or imported with a seed phrase or a private key | If every recovery method is permanently lost, on-chain assets may be unrecoverable | What is Gate Wallet (updated 2026-08-31) |
Sources: each exchange’s official help center and academy articles listed in the table, checked 2026-10-21. I didn’t find official explanations for the wallet products of the other 8 exchanges, so they’re not included.
Two things to keep in mind when reading this table. First, coins in a Web3 wallet are not in your exchange account, and the proof of reserves an exchange publishes counts user assets held in exchange accounts (see proof of reserves comparison); the Binance Wallet FAQ also states that it is self-custody and that users are responsible for safeguarding their assets and backing up the wallet. Second, an MPC wallet having no seed phrase does not mean it needs no backup: Binance Wallet needs at least 2 key shares to work, and the cloud share and the recovery password are your backup. Exchanges can also shut down wallet products: at the time, Bybit advised users to move their assets to a still-supported wallet before the deadline or risk losing them, and to delete the old addresses from their exchange address book so they wouldn’t deposit to them by mistake later.
Should you move crypto from an exchange to your own wallet?
Here are the risks on each side, side by side, so you can judge for yourself:
- Leaving it on the exchange: the thing to worry about is the platform. In past incidents, exchanges said they would cover the losses after a hack, and what users actually paid was waiting time: after Bitget was hacked in 2026, it took about 7.5 days before withdrawals were fully restored, and OKX, which wasn’t hacked in 2020, halted withdrawals for about 41 days because the person responsible for its private keys was assisting a police investigation (checked by this site on 2026-10-12; see exchange safety record). Accounts can also be restricted by risk controls; what to do is covered in what to do if your exchange account is frozen.
- Moving it to your own wallet: the thing to worry about is you. If you copy the seed phrase wrong, lose it, get tricked out of it, or sign a malicious approval, on-chain transfers can’t be reversed, and there is no fallback like resetting 2FA. OKX states that if the seed phrase is lost and the wallet is deleted, the assets cannot be recovered.
A common approach is to split by purpose: keep what you plan to trade soon on the exchange and set up your account security settings properly; consider moving to a self-custody wallet only the part you’ll hold long term, in amounts large enough that platform risk worries you. How much to split depends on how often you trade and how confident you are in keeping your own keys, and I won’t pick a ratio for you. Until you have a backup method ready, I don’t recommend moving large amounts to your own wallet.
What is a seed phrase, and are 12 words secure enough?
A seed phrase (also called a recovery phrase) turns a wallet’s private key into a list of English words; writing it down backs up the whole wallet. Most wallets follow Bitcoin’s BIP39 standard: the words come from a 2048-word list, and the phrase can be 12, 15, 18, 21 or 24 words long (BIP39 specification). Trezor also supports the 20-word SLIP39 format, which uses a 1024-word list; Ledger devices always use 24 words.
I ran the numbers from the BIP39 specification. Twelve words consist of a 128-bit random number plus a 4-bit checksum, giving 2 to the power of 128 possible combinations, about 3.4×1038; 24 words are 256 bits, about 1.16×1077 combinations. With that many combinations, guessing is impossible, so 12 words are already enough for a personal wallet and 24 words just add extra margin. In real cases of lost coins, the seed phrase was almost always seen, photographed, or typed into a fake website by the owner.
On storing a seed phrase, the official advice from several wallet makers is very consistent:
- Write it on paper; don’t take a screenshot: OKX states not to store it anywhere online, including chat apps, cloud drives and notes apps (OKX: what is a private key and seed phrase). Trezor also states that you shouldn’t keep digital copies: no screenshots, photos, emails, Dropbox or encrypted folders.
- Get the order right: Trezor asks you to write the words down in the order shown on screen. Once written, check it with the wallet’s built-in confirmation step; Ledger also has Recovery Check to confirm you copied it correctly.
- Protect it from fire and water, and keep it somewhere only you know: Ledger recommends an offline physical medium and also mentions metal storage products.
- Never give it to anyone who asks: OKX states, “If someone asks for your seed phrase, it’s a scam, no exceptions,” and Ledger also states it will never ask you for your 24 words.
- Don’t import a hardware wallet’s seed phrase into a software wallet on a phone or computer, which Ledger specifically warns about; once imported, that private key has effectively been on an internet-connected device.
BIP39 also has an optional passphrase: the same seed phrase with a different passphrase produces a different wallet. It adds a layer of protection, but if you forget the passphrase you can’t open the original wallet, even if you still have the seed phrase.
What are the most common ways people lose crypto?
Once you hold your own keys, what hackers go after is your seed phrase, your signature or your transfer address. These 5 come up again and again in wallet makers’ official guides:
- Phishing sites and fake support asking for your seed phrase: MetaMask states that there are only two situations where you need to enter your seed phrase: when you first create the wallet, to confirm you’ve written it down, and when you restore the wallet or reset your password. Other requests are most likely scams; legitimate websites and DApps won’t ask you to enter it (MetaMask: how to recognize the real MetaMask). For the tactics, see phishing and fake customer support.
- Fake apps and tampered hardware wallets: MetaMask states that you should install it only from the download page on its official site or from official browser extension stores. Ledger states that a genuine device never comes with a pre-set seed phrase or PIN, that you shouldn’t use one that does, and that you should run Genuine Check after receiving the device (Ledger: buying securely, updated 2026-09-18). Trezor also recommends buying from its official shop, its official Amazon store or authorized resellers (Trezor: where to buy a genuine device).
- Malicious approvals: when you approve a token on a DApp, the default allowance is often so large it’s practically unlimited, and if you approve a malicious or hacked contract, your tokens may be drained. MetaMask states that disconnecting your wallet from a DApp does not revoke an approval; revoking is an on-chain transaction that costs gas; you can review approvals with the token approval checkers on Etherscan, BscScan and Polygonscan, and it recommends checking regularly (for example, monthly) (MetaMask: how to revoke approvals).
- Address poisoning: the attacker sends you a zero-value or tiny transfer from an address whose first and last characters match an address you use often, so it shows up in your transaction history, and waits for you to copy the wrong address from that history next time. MetaMask recommends not copying addresses from transaction history, checking the characters in the middle of the address, saving frequently used addresses as contacts, and double-checking before large transfers (MetaMask: address poisoning scams).
- Choosing the wrong network: when the wallet and the exchange support different networks, picking the wrong chain can leave assets stuck or lost for good. Each exchange’s recovery rules are in what to do if you deposit on the wrong network.
Be careful with anyone who claims they can recover stolen coins, too. MetaMask states it never charges you anything to unlock a wallet or retrieve funds, including taxes or fees (MetaMask: common tax scams). If you’re in Taiwan and get a suspicious call or message, you can call the 165 anti-fraud hotline (165 反詐騙專線) to check; more tactics are collected in exchange scam types.
How do you withdraw from an exchange to a wallet?
Taking Binance as an example, on the website you go from [Assets] → [Overview] to the withdrawal page, choose [Withdraw], then enter the address (Binance: how to withdraw crypto, updated 2026-10-05). Other exchanges name their menus differently, but the steps are much the same:
- First, check in your wallet which network to receive on: open the wallet’s “Receive” page and choose the coin and network, for example TRC20, BEP20 or ERC20 for USDT. Binance states that the network you choose must match the network of the receiving platform, so pick a network the receiving side supports rather than just the cheapest one.
- Copy the address from the wallet’s receive page, paste it into the exchange, and compare the beginning, middle and end. Don’t copy it from transaction history or chat logs.
- Check whether you need a Memo (tag): networks such as XRP and EOS require one, and Binance states that without it, the recipient may not detect your deposit. Transfers to a personal wallet usually don’t need a Memo; go by what the wallet’s receive page shows.
- Send a small test to a new address first: Binance’s guide states, “We recommend sending a small amount of assets first to confirm that the address information is correct,” and then sending the rest once it arrives.
- Once confirmed, add it to the whitelist: when adding an address, Binance lets you tick “Add address to whitelist”, and once the whitelist is turned on you can only withdraw to addresses on it. How each exchange’s whitelist differs is covered in exchange account security settings.
- If the exchange asks you to verify wallet ownership, follow the on-screen steps: OKX states that digital signature verification only means signing a message in your wallet, moves no coins and costs no network fee, while a Satoshi test requires sending a set amount from the address being verified and does incur a network fee (OKX: why do I need to verify my private wallet address, updated 2026-10-16). Verification never requires your seed phrase.
One more thing people often overlook: once the coins are in your wallet, moving them out again costs on-chain fees. Gas on Ethereum must be paid in ETH (ethereum.org: Gas); calling a smart contract on TRON (a TRC20 USDT transfer is this kind of transaction) consumes energy, and when there isn’t enough energy, TRX is burned to pay for it (TRON resource model). So if your wallet holds only USDT and no ETH or TRX, the USDT can’t be sent out. For definitions, see TRC20 / ERC20 / BEP20.
How much extra does a small test transfer cost?
The extra cost of a test transfer is one withdrawal fee; the test amount itself arrives in your wallet and isn’t lost. Note that the test amount can’t be below the minimum withdrawal. Using the USDT figures read from 3 exchanges’ official APIs on 2026-10-21, I worked out the total fees for “test first, then send 1,000 USDT”:
| Exchange and network | Withdrawal fee (USDT) | Minimum withdrawal (USDT) | Extra cost of test | Test plus main transfer, total | Share of 1,000 USDT |
|---|---|---|---|---|---|
| Bitget, BEP20 | 0.01 | 5 | 0.01 | 0.02 | 0.002% |
| Bitget, TRC20 | 1.5 | 5 | 1.5 | 3 | 0.3% |
| KuCoin, TRC20 | 1.99 | 4 | 1.99 | 3.98 | 0.398% |
| KuCoin, ERC20 | 5.5 | 30 | 5.5 | 11 | 1.1% |
| HTX, TRC20 | 0.5 | 1 | 0.5 | 1 | 0.1% |
| HTX, BEP20 | 0.01 | 1 | 0.01 | 0.02 | 0.002% |
Sources: Bitget official coin API, KuCoin official currency API, HTX official currency API, read 2026-10-21. Fees change with network conditions, so go by the withdrawal screen; a full comparison of 13 exchanges is in USDT withdrawal fees.
As the table shows, the gap comes mainly from which network you pick. For the same test plus 1,000 USDT transfer, KuCoin on ERC20 costs 11 USDT in fees in total, while Bitget or HTX on BEP20 costs only 0.02 USDT. When your wallet supports a cheap network, the cost of testing is close to negligible. The more awkward part is the minimum withdrawal: KuCoin’s ERC20 minimum is 30 USDT, so the test amount has to be at least 30 USDT.
What are the risks of self-custody?
- There’s no customer support to turn to: if you lose the seed phrase, forget the passphrase, or delete the wallet without a backup, nobody can reset it for you. Trezor states that if you didn’t write down your backup and then forget your PIN or break the device, you lose access forever.
- On-chain transfers can’t be reversed: sending to the wrong address, falling for address poisoning, or signing a malicious approval can’t be undone once the transaction is on-chain.
- A leaked seed phrase means your wallet is gone: Ledger states that anyone who steals the paper with your seed phrase can easily get into your wallet. If your seed phrase may have leaked, MetaMask’s approach is to create a new wallet in another browser or on another device, write down the new seed phrase, move your remaining assets over, and then stop using the old wallet; it also states that transactions can’t be reversed and lost funds can’t be recovered (MetaMask: what to do if your account is compromised).
- Only one backup: a single sheet of paper is a single point of failure. A multisig wallet is one solution. Safe recommends a threshold above 1 and below the total number of signers, and gives 3 signers with a threshold of 2 (1 MetaMask plus 2 hardware wallets) as a common personal setup; the trade-off is that setup and every transfer are more complex.
- Wallet products can be discontinued: Bybit shut down Cloud Wallet and Keyless Wallet on 2025-05-31 and required users to move their assets before the deadline. If you use a wallet bundled with an exchange, keep an eye on official announcements.
Also keep in mind that when you trade futures on an exchange, leverage can get your position forcibly liquidated and cost you your entire margin, and that risk has nothing to do with which wallet your coins are in.
Does moving coins to a wallet affect your rebate?
No. A fee rebate depends only on your trades on the exchange; withdrawing coins to your own wallet after trading doesn’t affect the referral relationship. On exchanges you signed up for with this site’s referral codes, the exchange pays the rebate automatically based on the referral relationship. For example, with the Binance referral code KEVINWU, the current automatic exchange rebate is 20% (updated 2026-10-24); every exchange is listed in the crypto exchange referral codes roundup. Bybit has no automatic exchange rebate on this site; instead you bind your UID through Fee Otter. That extra rebate is paid by Fee Otter, not by the exchange and not by Kevin Wu, and the rate is whatever Fee Otter’s page shows; details are in Bybit fee rebate: Fee Otter. No rebate site ever needs your seed phrase or private key; anyone who asks for them is running a scam, and the warning signs are collected in rebate scam warning signs.
FAQ
Is a cold wallet always safer than a hot wallet?
A cold wallet’s private key isn’t online, so it avoids the risk of remote theft that a hot wallet has, but if the seed phrase leaks or you sign a malicious transaction, a cold wallet can be drained just the same. A hardware wallet lets you confirm the receiving address on the device, and MetaMask lists this as one way to guard against address poisoning.
If I lose the Web3 wallet in an exchange app, can the exchange recover it?
In most cases no, because these wallets are self-custody. The official Binance Wallet FAQ states that if you forget the recovery password or lose the cloud backup and also lose the device or delete the app, Binance cannot recover the wallet for you; OKX also states that if the seed phrase is lost and the wallet is deleted, the assets cannot be recovered.
Can I photograph my seed phrase or store it in the cloud?
No. The official guides from OKX, Trezor and Ledger all require offline storage. OKX states not to take screenshots or store it in chat apps, cloud drives or notes apps; Trezor states not to use screenshots, photos, emails, Dropbox or encrypted folders.
What’s the difference between a 12-word and a 24-word seed phrase?
Twelve words represent a 128-bit random number and 24 words represent 256 bits; neither can be brute-forced. Under the BIP39 specification, 12 words have about 3.4×1038 possible combinations. Ledger devices always use 24 words, and Trezor uses 12, 20 or 24 words depending on the model and settings.
Should I do a small test before withdrawing from an exchange to a wallet?
A test is recommended the first time you withdraw to a new address, and Binance’s withdrawal guide recommends the same. The extra cost is one withdrawal fee; the USDT fees found on 2026-10-21 ranged from 0.01 USDT on BEP20 to 5.5 USDT on KuCoin ERC20. The test amount can’t be below the minimum withdrawal.
Why can’t I send USDT out after withdrawing it to my wallet?
The most common reason is that the wallet has none of the chain’s native coin to pay the fee. Gas on Ethereum is paid in ETH; a USDT transfer on TRON consumes energy, and when energy runs short, TRX is burned. Send a little ETH or TRX to the same address first, and you’ll be able to send the USDT.
Does disconnecting my wallet from a DApp cancel the approval?
No, disconnecting doesn’t revoke a token approval. MetaMask states that revoking an approval requires sending a separate on-chain transaction and paying gas; you can review and revoke approvals with the token approval checkers on Etherscan, BscScan and Polygonscan, and it recommends checking regularly, for example once a month.
Can I buy a secondhand hardware wallet on an online marketplace?
Not recommended; buy a hardware wallet from the official store or an authorized reseller. Ledger states that a genuine device never comes with a pre-set seed phrase or PIN and that you should run Genuine Check after receiving it; Trezor states that devices bought from its official shop, its official Amazon store or authorized resellers can generally be considered safe.
For the exchanges’ own hack history, see exchange safety record; for each exchange’s proof of reserves, see proof of reserves comparison. For the terms and arrival rules to check before you withdraw, see deposit and withdrawal terms explained, and if this is your first time buying crypto, start with buying crypto for the first time.