# Use a cold wallet with FxWallet

> Turn a spare phone that stays offline into a cold wallet. It keeps your keys and signs by QR code, while your everyday phone sends transactions.

URL: https://docs.fxwallet.com/cold-and-hardware-wallets/cold-wallet-mode
Last reviewed: 25 September 2026

A cold wallet keeps your keys on a phone that never goes online, so you need two phones:

- The **offline phone**, usually a spare one, holds the wallet's keys and only signs. It runs FxWallet 2.17.7 or later (or imToken 2.15.0 or later) with no internet connection. To sign Siacoin (SC) transactions that an online phone with FxWallet 3.3.0 or later prepares, the offline phone needs FxWallet 3.3.0 or later too.
- The **online phone** runs FxWallet as usual. It shows your balances and prepares transactions, but holds no keys.

The phones pass transactions to each other as QR codes, so the keys never leave the offline phone.

Cold wallet mode isn't for hardware wallets. FxWallet connects [Keystone](https://docs.fxwallet.com/cold-and-hardware-wallets/keystone) and [Goldshell](https://docs.fxwallet.com/cold-and-hardware-wallets/goldshell) hardware wallets, and can't connect a Ledger or a Trezor.

## Set up the offline phone

1. Reset the phone to its factory settings, which erases everything on it, then install FxWallet. On Android, install the APK from [www.fxwallet.com/download](https://www.fxwallet.com/download#apk) if the phone can run it, rather than Google Play: you can then update FxWallet later without going online.
2. Turn on airplane mode, and check that Wi-Fi, mobile data and Bluetooth are off. FxWallet switches to cold mode only when the phone has no connection at all: a Wi-Fi network without internet access still counts as a connection.
3. Open FxWallet. In cold mode, the home screen shows **Connect** next to **Send**, **Receive** and **Scan**, and the other tabs show **The cold wallet is currently unable to access this feature.**
4. Create a wallet, or import one with its mnemonic phrase. Offline, FxWallet only works with wallets that have a mnemonic phrase.
5. Write the mnemonic phrase down on paper and keep it offline. See [Back up your mnemonic](https://docs.fxwallet.com/get-started/back-up-your-mnemonic).

> **Danger**
>
> Keep the offline phone disconnected from the internet from now on. Once it goes online, its keys are no longer cold.

## Connect it to your online phone

1. On the online phone, tap **Import Existing Wallet** on the first screen. If you already have a wallet there, tap the wallet name at the top of the **Wallet** tab, then tap **+**. Then tap **Cold / Hardware Wallet** → **Cold Wallet**.
2. On the offline phone, tap **Connect** on the home screen, next to **Send**, **Receive** and **Scan**. It shows a QR code. With imToken, tap the ">" icon on the wallet page, then select "Connect with other wallets".
3. On the online phone, tap **Scan to Connect** and scan the QR code.
4. Under **Add Accounts**, select the accounts to add, then tap **Confirm**.

On the online phone, the wallet is marked **Cold Wallet**. It can't sign anything without the offline phone.

## Send from a cold wallet

1. On the online phone, start the transaction as usual. FxWallet shows **Offline Signature** with a QR code.
2. On the offline phone, tap **Scan** and scan that QR code. Check the **Payment Details**, tap **Confirm** and verify it's you. The offline phone now shows a signed QR code.
3. On the online phone, tap **I have signed with my wallet**, scan the offline phone's QR code, and confirm to broadcast.

If you pay the network fee with a Gas Card, you sign twice on the offline phone, and must finish both steps within a time limit.

**Signing History** lists your signing requests: on the online phone, tap **More** → **Signing History** on the **Wallet** tab; on the offline phone, tap the icon at the top right. It shows whether a request was signed, not whether the transaction succeeded on the blockchain.

## Add accounts or networks

To add an account, create it on the offline phone, then scan its **Connect** QR code again from the online phone: only the new accounts can be selected.

When FxWallet adds support for new networks, the online phone shows "Now supported" with **Add via your cold wallet**. Tap it and follow the steps: the offline phone adds the networks, and you scan its QR code again.

## If something doesn't match

- No **Connect** on the offline phone: it still has a connection, often a Wi-Fi network without internet access. Turn on airplane mode, then turn Wi-Fi off.
- **Wallet Mismatch**: the QR code comes from a different cold wallet.
- **Account Mismatch**: on the offline phone, switch to the account the transaction uses, then scan again.
- **Account Not Found**: the account isn't on the offline phone. Create it there first.
- "Use offline wallet to sign.": the offline phone is connected to the internet. Disconnect it.
- "Offline wallet does not support this chain.": the offline phone can't sign for this network.