To swap ETH to BTC without an exchange, send ETH from your own Ethereum address to a native swap route and receive real BTC at your own Bitcoin address. You sign one Ethereum transaction and pay its gas in ETH. The route pays for the Bitcoin transaction that delivers your coins and takes that fee out of the BTC you receive.
What is different about this pair
A native swap works the same way in both directions. How to swap BTC to ETH without a bridge has the general walk-through and cross-chain swaps explained the background. This guide covers only what changes when Ethereum is the sending side and Bitcoin the receiving side.
- You start on a fast chain. Ethereum divides time into twelve-second slots with one block each. The route sees your deposit within a minute or two.
- Gas is the moving part. It is paid in ETH, on top of the amount, and it climbs when Ethereum is busy.
- Tokens need one more transaction. ETH itself needs no approval. An ERC-20 token such as USDC does.
- The payout is a Bitcoin transaction. Its fee depends on the size of that transaction in bytes, not on how much BTC it carries.
- Bitcoin has several address formats and a minimum size for an output. Both matter on the receiving side.
Before you start
- ETH on Ethereum itself, in a self-custody wallet. ETH on Arbitrum or Base sits at the same address but is a separate balance on another network.
- More ETH than you want to swap. If you hold tokens on Ethereum, you also need ETH afterwards to move them.
- A Bitcoin address you control. A multi-chain wallet such as THORWallet gives you one next to your Ethereum address. See the Bitcoin wallet and Ethereum wallet pages.
- An amount that is large next to the Bitcoin payout fee.
The steps
- Open the swap screen. Pay with ETH on Ethereum and receive BTC.
- Enter the amount. Do not enter your whole ETH balance.
- Compare the routes by the BTC you receive and by the estimated time.
- If you swap an ERC-20 token instead of ETH, approve it first. That is a separate Ethereum transaction with its own gas. THORWallet shows an Approve contract screen where you can set a custom amount instead of an unlimited one. See token approvals.
- Check the destination. It should be the Bitcoin address of your own wallet.
- Review the gas fee, the outbound fee and the minimum amount you accept. Then sign.
- Follow the swap until the payout step shows a Bitcoin transaction ID.
- Wait for that Bitcoin transaction to confirm before you treat the BTC as spendable.
THORWallet has a page for this pair: swap ETH to BTC. It compares several routes, and which of them answer depends on the pair and the amount.
How long it takes and why
In a BTC to ETH swap, the route sits and waits for Bitcoin to confirm your deposit. Here the deposit is on Ethereum, so that part shrinks from tens of minutes to a minute or two. Three things remain.
- Deposit safety margin. A route does not act on the first block. It waits until a reorganization of the chain is unlikely. Chainflip's documentation, for example, names 7 blocks on Ethereum, about 84 seconds, against 3 blocks on Bitcoin, about 30 minutes.
- Route time. Some routes hold a payout for a set time before they send it, and a streaming route works through a large amount in parts on purpose. Read the estimate on each route.
- Your side of the payout. The route's job ends when it broadcasts the Bitcoin transaction. Your wallet shows the BTC as unconfirmed until a Bitcoin block includes it, which takes about ten minutes on average and sometimes much longer. If you try to swap coins that arrived a moment ago, THORWallet tells you they are still confirming.
An exchange that already holds your ETH trades it at once, and that is faster. Withdrawing the BTC to your own address afterwards needs the same Bitcoin block.
What it costs
| Cost | Paid to | For this pair |
|---|---|---|
| Ethereum gas | The base fee is burned, the tip goes to validators | Paid in ETH on top of the amount. A plain ETH transfer uses 21,000 units of gas. A call to a route's contract uses more. |
| Approval gas | Same as above | Only when you swap an ERC-20 token. A second Ethereum transaction. |
| Liquidity fee and price impact | The route's liquidity providers or market makers | Inside the quote. Grows with the size of the swap. |
| Outbound fee | The route, to pay Bitcoin miners for the payout | Taken from the BTC you receive. Follows Bitcoin's fee level, not your amount. |
| Wallet service fee | The wallet | In THORWallet: none under $100, 1.25% standard from $100 to $50,000, lower with a Community Tier or on larger swaps. |
Two details help you read these numbers.
Your wallet sets a maximum for gas. Ethereum charges the base fee plus the tip and refunds the difference, so the final gas cost can come in below the figure on the review screen. When demand is high, users outbid each other with higher tips, and the same swap can cost several times more than an hour earlier.
The outbound fee is where small swaps lose. Bitcoin fees are priced per byte, so a payout of 0.001 BTC costs the route as much as a payout of 1 BTC. THORChain's documentation computes the fee as transaction size times the current gas rate times a multiplier, and advises swapping at least four times the larger of the outbound fee and $1. If the payout fee would consume the output, THORWallet blocks the swap with an "Amount too low" message. Crypto swap fees explained goes through each line.
Common mistakes
- Swapping your last ETH. Without ETH you cannot pay gas. Tokens left on Ethereum are then stuck until you buy ETH again, and revoking an old approval costs gas as well.
- Approving an unlimited amount for a one-off token swap. The approval stays active after the swap. Approve the amount you swap, or revoke it afterwards.
- Signing during a gas spike. If the swap is not urgent, check again later.
- Collecting many small payouts. Each payout arrives as a separate coin in your Bitcoin wallet. Spending many small coins later makes a larger and more expensive transaction. Bitcoin nodes do not relay outputs below a minimum size at all, 546 satoshis for the older address types with default settings.
- Typing or editing a Bitcoin address. The older address types use the mixed-case Base58 format. Native SegWit addresses use Bech32, start with bc1 and are written in lowercase. Use the address on your wallet's receive screen, and paste it or scan it.
- Picking ETH on the wrong network. The address is the same on Ethereum, Arbitrum and Base. The balance is not.
- Calling the swap finished too early. A payout that is broadcast is not yet confirmed. Do not promise the BTC to anyone before the Bitcoin block.
An Ethereum transaction and a Bitcoin payout are both final. Before you sign, check that you pay with ETH on Ethereum, that the destination is your own Bitcoin address and that enough ETH stays behind for gas.
How to do it in THORWallet
Step-by-step articles from the help center, checked against the current app.
- How to make a swapStep-by-step instructions for swapping one coin for another in the THORWallet app and in the web app.
- Token approvals: review and revokeWhat a token approval (allowance) is, why unlimited approvals are a risk, and how to review and revoke approvals in THORWallet.
- Swap fees and how to lower themWhich fees a swap has, what the THORWallet fee is for each Community Tier and swap size, and how to pay less.
- How to track a swapWhere to find a swap after you confirm it, what each status means and how to open the transaction in a block explorer.
- My swap is stuck, delayed or refundedWhat to do when a swap stays pending, was refunded or shows Status unknown, where a refund arrives and what to send to support.
Sources
- ethereum.org developer docs: gas and fees
- ethereum.org developer docs: blocks and slots
- Bitcoin developer guide: transactions, fees and minimum output size
- bitcoin.org: FAQ on block times and confirmations
- BIP-173: Bech32 address format for native SegWit
- THORChain developer docs: fees and the outbound fee
- Chainflip docs: swapping basics, deposit safety margins and refunds
Reviewed on 12 Nov 2026. Statements about THORWallet were checked against the help center, and the sources above were opened on that day. This guide explains how things work. It is not financial advice.