# Welcome to O3 Cross-Chain Wallet O3 cross-chain wallet is a mobile cross-chain smart wallet specially created for DeFi users. It supports one-click switch and custom network of any EVM-compatible chain; built-in cross-chain bridge allows users to safely store encrypted assets while conducting convenient, efficient, and low-cost cross-chain exchange. **What you will find here:** {% content-ref url="/pages/LDtVqrNbDXFqRw1oR8iA" %} [Quick Start](/guides/quick-start) {% endcontent-ref %} {% content-ref url="/pages/8L44w7r1FxQCuxq3skNX" %} [Manage Your Crypto Assets](/guides/manage-your-crypto-assets) {% endcontent-ref %} {% content-ref url="/pages/AFt1boT58lJUFHtySrBp" %} [Swap](/guides/swap) {% endcontent-ref %} {% content-ref url="/pages/KsxrXgwjVrgz54YJ34ZJ" %} [Wallet Q\&A](/guides/wallet-q-and-a) {% endcontent-ref %} # O3 Cross-Chain Wallet Asset Management, Swap, Bridge, Gas Station... All in O3！ O3 cross-chain wallet is a mobile cross-chain smart wallet specially created for DeFi users, operating independently of the O3 Wallet. It supports one-click switching and customization of any EVM-compatible chains with user-friendly interface. The O3 cross-chain wallet also has a built-in cross-chain DEX aggregator. Asset Management, Swap, Bridge, Gas Station... All in O3! Users can explore the Web3.0 world at the tip of their fingers. ### Safe and Reliable Digital Asset management Service As an 100% non-custodial cross-chain smart wallet, O3 cross-chain wallet supports one-click switching of any EVM-compatible chains including Ethereum, BNB Chain, Polygon, Optimism, Arbitrum, Avalanche, OKC, Heco, etc., and custom networks. More importantly, O3 cross-chain wallet can safely store crypto assets on multiple blockchains with only one set of mnemonic phrases/private keys. ![](/files/Cvixiymfm7yaEAJAPJ3d) #### Manage Your O3 Cross-Chain Wallet * Take ownership of you private keys and assets. O3 will never store your private information or sensitive data. * Set up contact addresses to quickly send/receive assets. * Log into your wallet with Fingerprint/Face ID. * Support multiple languages and currencies. * Real-time tracking of all your transactions. ### Handheld Cross-Chain DEX Aggregator In addition to the basic functions of a high-quality encrypted wallet, O3 cross-chain wallet also incorporates the functionalities of Bridge, Swap, and Gas Station offered in O3 Interchange. By aggregating the liquidity of multiple DEXs, users have more choices on cross-chain transactions and are no longer limited to cross-chain symmetric assets. Through the wallet, real-time cross-chain transaction of any asymmetric native assets, and even the swap of main assets (Gas) on any EVM-compatible chain can be realized. It saves users the process of going to CEXs to buy, sell and send assets. In the future, O3 cross-chain wallet will integrate more DEXs and cross-chain bridges to further improve efficiency. ![](/files/fuKp2Qi0OkJH68b8ki1P) ### 3-in-1 Auto-Shift When we designed the O3 cross-chain wallet,our goal was to deliver a user-friendly, intuitive and easy-to-use product. Therefore, whether you are a DeFi newbie or seasoned investor, you only need to click the "Swap" button to initiate a cross-chain transaction. ![](/files/g0h6VOWcIgawuFPXdjKP) #### Let's Look at Some Details For easy reference, users can search for a recent transaction on the recent transaction list. When a cross-chain exchange is in progress, the blank space at the bottom of Swap page will display the progress in real-time. Of course, you can also customize the slippage. Just like that, a safe, direct and cost-effective asset exchange is completed in O3 cross-chain wallet. We hope that O3 cross-chain wallet can provide users with a refreshing visual experience, in addition to helping users store, manage and transfer their crypto assets . # Quick Start Welcome to O3 cross-chain wallet User Guide. What you will find here: {% content-ref url="/pages/nvspR37GXAZ3w64dpAFg" %} [How to Download O3 Cross-Chain Wallet](/guides/quick-start/how-to-download-o3-cross-chain-wallet) {% endcontent-ref %} {% content-ref url="/pages/v7gxxNLTFAcxRW8I8GAa" %} [How to Switch Wallet Network to BNB and OKC Chain](/guides/quick-start/how-to-switch-wallet-network-to-bnb-and-okc-chain) {% endcontent-ref %} {% content-ref url="/pages/eStKyZ6joxbKy4Q5pEfe" %} [How to Backup Your Wallet Safely\Properly](/guides/quick-start/how-to-backup-your-wallet-safely-properly) {% endcontent-ref %} {% content-ref url="/pages/YNkpn4BMjSl1E1DnuTZ8" %} [How to Import Assets from Other Wallets to O3 Cross-Chain Wallet](/guides/quick-start/how-to-import-assets-from-other-wallets-to-o3-cross-chain-wallet) {% endcontent-ref %} {% content-ref url="/pages/dBdTmJEIRlotaCuXOF59" %} [How to Switch Between EVM-Chains](/guides/quick-start/how-to-switch-between-evm-chains) {% endcontent-ref %} {% content-ref url="/pages/moLGcwCY8yW7ARmrq44N" %} [How to Add Custom Networks](/guides/quick-start/how-to-add-custom-networks) {% endcontent-ref %} {% content-ref url="/pages/WiQbCq6pF0zfxtEIUs9j" %} [Private Key / Secret Recovery Phrase / Keystore](/guides/quick-start/private-key-secret-recovery-phrase-keystore) {% endcontent-ref %} # How to Download O3 Cross-Chain Wallet {% hint style="info" %} Please make sure it is the official link before downloading: {% endhint %} ### Android **Step 1:** Open the O3 Wallet official website (), click \[Android Latest(.APK)] to download. Alternatively, you can search for "O3 Cross-Chain Wallet" on Google Play to download; ![](/files/lWajE1JuiTDQkIIz9fgU) **Step 2:** Find the downloaded APK file and click Install; **Step 3:** Open the installed O3, and Create/Import a wallet. ### iOS **Step 1:** Go to the official website () and click 「App Store」 to download and install it. If it says "App Unavailable", which means O3 has not been listed on the App Store in the region where your ID is registered, you need to change the Apple ID and download it again. ![](/files/Lp1qHYdwMffKEpKYjYhv) Remember to double-check the logo of the wallet before installation**.** ![](/files/AMvo1EOKXUo16uFenha1) **Step 2:** Open the installed O3 and Create/Import a wallet. # How to Create an O3 Cross-Chain Wallet {% hint style="info" %} This section is divided into two parts: 1\. You are creating an O3 wallet for the first time. 2\. You have already created an Ethereum wallet in O3 and want to create another wallet with a different address. {% endhint %} ### 1. Using O3 for the first time **Step 1:** Open the downloaded O3, click \[Create Wallet], read and accept the Terms of Service and Privacy Policy. IOS users will enter the wallet creation page directly, and Android users need to click \[Create Wallet] to enter the wallet creation page. ![](/files/42sJBnNjTmUQFaIWOVmW) **Step 2:** Enter your preferred wallet name. The password is required to have at least 8 characters of numbers + letters. Then type in the password again and confirm your wallet password. ![](/files/WFEOBrJ58tBf3xTMoOGw) **Step 3:** Follow the same instructions above to create and backup your new wallet. **Step 4:** Entering wallet backup page. Backup is the most important step in wallet creation and also the final step for successfully creating your wallet. Click the \[Backup] button to back up your wallet 's Secret Recovery Phrase safely and correctly. ![](/files/dy7QEwUCh68aX75MyXXJ) **Step 5:** Entering the Secret Recovery Phrase backup verification page. Fill in the Secret Recovery Phrase correctly in their designated order. After completing the steps above, your O3 Cross-Chain Wallet is officially created. Start your cross-chain journey with O3 now! ### 2. Creating Another Wallet with a Different Address If you already have an O3 wallet and would like to create another wallet with a different address, please refer to the steps below: **Step 1:** \[Me ]—— \[Manage Wallet]; **Step 2:** Click \[+] —— \[Create Wallet]； **Step 3:** Follow the instructions, create and backup your new wallet. # Private Key / Secret Recovery Phrase / Keystore ### Private Key The private key is 64 random hex characters. Each wallet has only one immutable private key. Whoever owns the private key has control over the assets. Thus, it is extremely important to keep your private key safe and do not tell anyone. **When backing up the private key, users need to pay extra attention to the distinction between upper and lower case**. ### Secret Recovery Phrase The Secret Recovery Phrase is composed of 12 words. The "Secret Recovery Phrase" and "Private Key" have the same function. The main purpose of the "Secret Recovery Phrase" is to simplify the wallet backup process, as the private key is a complicated string of numbers and letters which are prone to error when backing up. The Secret Recovery Phrase may support multiple languages, including English, Simplified Chinese, Japanese, French, etc. but O3 only uses an English thesaurus. If the Secret Recovery Phrase that you backed up is not from the English thesaurus, it may be incompatible when importing into the wallet, but the private key and Keystore are the same. #### Secret Recovery Phrase Backup: * Make sure you back up the Secret Recovery Phrase. If you forget the wallet password, or want to change the password, you need to use the Secret Recovery Phrase reset the password (the private key can also be imported to reset the password); * Remember not to use screenshots or photos when backing up the Secret Recovery Phrase. It is recommended to use a physical medium, such as copying by hand, keep the backup in a place that you think is safe, and away from third parties; * Never use email or other instant messaging methods to send your Secret Recovery Phrase. ### Keystore It can be understood as the encrypted "private key", which is also related to the password of the wallet. If the wallet password is changed, the Keystore also changes accordingly. When importing a wallet with Keystore, the corresponding password is still needed. Therefore, the Keystore needs to be backed up with the password, but remember to store separately. {% hint style="info" %} Please note that the wallet password must be available if you want to use the Keystore. Once you forget the password, you will lose the right to use the Keystore. {% endhint %} # How to Backup Your Wallet Safely\Properly {% hint style="info" %} **Reminder:** The backup of your wallet is the only way for you to retrieve your assets, so please keep it safe. The Secret Recovery Phrase has the same function as the private key, so it is recommended to back up the Secret Recovery Phrase. {% endhint %} **Click the \[Detail] button on the O3 Wallet homepage → \[Backup Wallet] → \[Secret Recovery Phrase / Private Key /Keystore], enter the wallet password to back up your phrase.** ![](/files/agNClT0zPN69OFL4JuUj) ### Backup Private Key: The private key are a combination of numbers, upper and lower case letters. Therefore, users must pay extra attention to the distinction between numbers and the upper/lower case of letters when backing up. We recommend you to copy the private key by hand and keep it away from the internet. ### Backup Secret Recovery Phrase The Secret Recovery Phrase are another form of the private key, usually composed of 12 random words. Compared to the private key, we strongly recommend users back up the Secret Recovery Phrase because a block of words are easier to back up than private key. In O3 cross-chain wallet, one set of Secret Recovery Phrase can manage assets on multiple EVM-compatible chains. When backing up, you need to copy the block of words in the order they appear. ### Backup Keystore Keystore are the encrypted version of the private key. Although it is encrypted, we cannot let down our guard and use internet or USB flash disk while backing up. In additon, it needs to be backed up with the current password. # How to Import Different Wallets ### Methods for Importing a Wallet Step 1： Method 1: Click the small icon in the upper left corner of the wallet homepage. Method 2: \[Me] — \[Manage Wallet]. Step 2: 1. On the Manage Wallet page, click \[+]; 2. Select the import method, Secret Recovery Phrase/Private Key/Keystore; 3. Enter the information correctly based on your selection, and finish setting up the wallet, including wallet name and password; 4. Click \[Import]. ![](/files/nL8h8pPc5ktFwbmOKAAl) ### Tips: * When entering the Secret Recovery Phrase, separate words with spaces; When importing Keystore, the original password is required. * If you find the wallet address is incorrect after importing, you can check whether the Secret Recovery Phrase, Private Key, or Keystore are backed up correctly. * If you import the private key, you won't see the Secret Recovery Phrase on the backup page of the wallet. # How to Switch Between EVM-Chains ### Switch Network Enter the wallet home page, click \[Ethereum Mainnet] at the top to enter the \[Switch Network] page. Select the EVM network you want to switch, such as BNB Chain, Polygon, etc... You can find other EVM-compatible networks in \[Other Networks]. If you are having trouble locating the network you want, you can add it through \[Add Quickly] and \[Customize] in the \[Customize] below. ![](/files/W4NIkzRemUaiH1kgm1hJ) ### Switch Back to Ethereum Mainnet Click the network name at the top of the wallet home page, such as BNB Chain, and select the \[Ethereum Mainnet] under \[Mainnet] on the \[Switch Network] page. ![](/files/E9buIY3ZT2PV01aXZBJM) # How to Add Custom Networks **Custom network functions are divided into Add Quickly and Customize.** ![](/files/U8MxsbsZ9IncpnJIewP3) ### Add Quickly: Click \[Add Quickly] to enter the EVM box. You can add the desired network by searching in the search bar, or scrolling down to select the network that you want to add. Then click \[+] on the right to add the network. ### Customize: Click \[Customize] to enter the \[Add Network] page; In the Add Network page, enter the required information such as the Network Name, RPC URL, and chain ID, then click \[Save]. {% hint style="info" %} Tips: When adding a custom network, please make sure the information that you entered are sourced from credible authorities or trusted third-party providers. {% endhint %} # How to Switch Wallet Network to BNB and OKC Chain **O3 supports one-click switching between any EVM-compatible network.** 1. Go to the wallet homepage, and click on the \[Ethereum Mainnet] at the very top. 2. On the Switch Network page, select BNB Chain or your desired network to switch the network. ![](/files/Dr4n98gFysJcHoazJo6y) # How to Import Assets from Other Wallets to O3 Cross-Chain Wallet {% hint style="info" %} O3 cross-chain wallet supports asset importation from any EVM-compatible chain. You can choose to import a wallet according to your backed-up private key or the Secret Recovery Phrase. {% endhint %} ### Import Method: 1.Me -> \[Manage Wallet]; 2.Click \[+]; 3\. Select the import method, Secret Recovery Phrase/Private Key/Keystore; 4\. According to the import method you choose, enter the information correctly; 5\. Click \[Import]. ![](/files/1EU3b9SlWQTmw8jgjQ0R) ### Tips: * When entering the Secret Recovery Phrase, separate words with spaces; When importing Keystore, the wallet password is required. * If you find the address is incorrect after importing, you should check whether the Secret Recovery Phrase, Private Key, or Keystore are backed up correctly. * If you import the private key, you won’t see the Secret Recovery Phrase on the wallet backup page. # Manage Your Crypto Assets {% content-ref url="/pages/2veG9722meRFQVSt79eP" %} [What is My Wallet Address?](/guides/manage-your-crypto-assets/what-is-my-wallet-address) {% endcontent-ref %} {% content-ref url="/pages/eR3jnU6BZe9frbZt1Ywx" %} [How to Add/Manage Assets](/guides/manage-your-crypto-assets/how-to-add-manage-assets) {% endcontent-ref %} {% content-ref url="/pages/1A173l9Dr4LGlaa6zevw" %} [How to Send/Receive?](/guides/manage-your-crypto-assets/how-to-send-receive) {% endcontent-ref %} {% content-ref url="/pages/igxTBmvRt0tQdAh2ohKO" %} [How to Set Up Fingerprint Recognition/Face ID?](/guides/manage-your-crypto-assets/how-to-set-up-fingerprint-recognition-face-id) {% endcontent-ref %} {% content-ref url="/pages/q481QHFiz6KjBnJayiHS" %} [What is Gas?](/guides/manage-your-crypto-assets/what-is-gas) {% endcontent-ref %} {% content-ref url="/pages/haZleP1XpeLlJlG0tjJh" %} [What is Data？](/guides/manage-your-crypto-assets/what-is-data) {% endcontent-ref %} # What is My Wallet Address? The wallet address is generated by the public key. The public key is derived from the private key through an elliptic curve encryption algorithm. Specifically, the wallet address are a combination of 64 random hex characters. When you are making a transfer, you need to show your address to the other party. {% hint style="info" %} The public key can be deduced by the private key and also used to generate the wallet address (Private Key -> Public Key -> Wallet Address) but cannot be reverse-engineered. {% endhint %} Different public chains have different corresponding asset addresses. The wallet addresses of EVM-compatible chains all start with “0”. After the O3 cross-chain wallet is successfully created, you can view your wallet address which is a string of numbers and letters starting with “0” embedded in the official background color of the respective EVM-compatible chain at the top of the asset homepage. Alternatively, you can click the \[Receive] button to view the wallet address in the form of a QR code. ![](/files/OnLbQNa1JrbS0WFIFvJy) # How to Add/Manage Assets Click the \[+] button on your wallet homepage to enter the \[Management] page. **The asset management page is divided into Management , Search Bar and Popular Assets.** ![](/files/V5E6ihXaKFzjxzlZsGT7) ### How to Add Assets: Enter the Token name in the search bar to search and add your asset, or check the popular asset to see if there is an asset you need to add. Then click \[+] to add assets to the wallet homepage. ### Sort/Remove Assets Appeared on the Homepage: Click \[Management] on the management page. You can sort your assets by pressing and holding the sorting icon on the right of whichever asset you want to rearrange. Click the small icon on the upper right corner to delete any assets that you do not want to appear on the homepage. ![](/files/w1WlLDcPEWgLP7LUnfnm) ### All My Assets: This page will display all the assets you added on the home page. Click on each asset to view its corresponding description. # How to Send/Receive? ### How to use O3 to transfer funds? #### The Common Transfer Methods: 1. Click \[Send] on the homepage to enter the asset transfer page; 2. Enter the recipient’s wallet address; 3. Choose the type of asset and enter the amount you want to transfer; 4. Set the gas fee. O3’s default setting is the most optimal. Alternatively, you can select \[fast], \[best], \[slow] from the standard column. Of course, you can customize the gas fee yourself; 5. After the above information is entered correctly and gas fee confirmed, you can click \[Next] to initiate transfer. {% hint style="info" %} Reminder: In the Ethereum Network, the higher the gas fee you provide, the faster the transaction is packaged. Please set a reasonable gas fee according to your transfer needs. {% endhint %} #### Other Transfer Methods: In addition to entering the address to transfer money, you can also transfer money by scanning the QR code of the receiving address. You can also add and select your frequently-used addresses. #### Add Contact Address: Click the \[Settings] button in the upper right corner of the wallet homepage and select \[contact address]. Click \[+] in the upper right corner to add your frequently-used addresses and customized name. ### How do I Receive Money with O3? Click \[Receive] on the home page to copy your wallet address or take a screenshot of the QR code of your wallet. Send your copied address or saved QR code to the other party. # How to Set Up Fingerprint Recognition/Face ID? ### iOS:Face ID * Go to the O3 wallet homepage, tap \[Me] on the bottom right of your screen; * Go to general settings; * Turn on Face ID, and click \[OK]. iOS users cannot use fingerprint recognition. ### Android:Fingerprint Recognition * Go to the O3 wallet homepage, tap \[Me] on the bottom right of your screen; * Go to general settings; * Turn on Fingerprint Recognition, and click \[OK]. Android users cannot use Face ID. # What is Gas? Whether it is the Ethereum network or other EVM-compatible networks, all operations on the blockchain need to consume Gas, just like a car needs to consume fuel. {% hint style="info" %} Gas Fee = Gas Price \* Gas Limit {% endhint %} ### Gas Price In the Ethereum Network, Gas Price can be set by the users. The unit for gas price is Gwei, 1 Gwei = 10^9 Wei. {% hint style="info" %} ETH, GWEI, WEI conversion: 1 ETH = 10^9 Gwei = 10^18 Wei {% endhint %} Gas Price is related to the transaction’s package speed. The higher the gas price you are willing to pay, the more incentivizing for miners to package your transaction on priority. ### Gas Limit Gas Limit is the maximum amount of gas a user can consume to conduct a transaction which is usually fixed at 21000 Gas. The Ethereum Yellowpaper pointed out that each transaction needs 21000 Gas, which is why the default gas limit setting in the Gas Fee page is 21000. If you need to change the gas fee, you can go to gas fee - customize - gas. However, it is recommended that you do not set the gas fee lower than 21000. ### How should I Select the Gas Fee when I Initiate a Transaction? In the gas fee page, O3 offers three gas fee options: "Fast", "Optimal", "Slow". You can select the gas fee option according to your own transfer needs. # What is EIP-1559? EIP-1559 was raised by Vitalik in 2019, standing for “Ethereum Improvement Proposal” , which aims to improve the efficiency of the fee market mechanism of Ethereum. It makes the gas fee more predictable and transparent, handles surges more efficiently, and reduces latency in transaction confirmations, thereby capturing greater Ethereum value. **EIP-1559 mainly changes the fee market mechanism of Ethereum, that is, the First-price Auction conducted by users was modified to the combination of Base Fee and Priority Fee.** **The Base Fee** automatically adjusts the Gas Price which is required for on-chain operations based on the space utilization of the previous block to cope with transient network congestion. Unlike the original miner fee mechanism, the Base Fee for EIP-1559 will be completely burned rather than given to miners. **Here is the formula for the dynamic adjustment of the Base Fee:** * If the previous block space utilization is 100% , which means the network is highly congested, then the current block BaseFee will automatically increase by 12.5%; * If the previous block space utilization is 0%, the current block Base Fee is automatically reduced by 12.5%. **Priority Fee**, a new type of transaction added by EIP-1559, is used to motivate miners to package the transaction during periods of high congestion. In addition, in order to protect the rights and benefits of users, to complete the upper limit of the tip that the user set and to improve the efficiency of winding, the EIP-1559 also allows users to set the Max Fee that is the maximum price you pay for each unit of gas and the Max Priority Fee that is the maximum tip you pay for each unit of gas. **According to the formula, Max Fee = Base Fee + Max Priority Fee, Max Fee and Max Priority Fee both support user-setting, and Base Fee is automatically given by the algorithm. If the miner fee (Base Fee + Tip) exceeds the Max Price, the exceeded fee will be refunded to the user.** {% hint style="info" %} Since the Base Fee is to be burned, only Priority Fees are charged by miners in EIP-1559. {% endhint %} At present, O3 cross-chain wallet has supported EIP-1559, you can follow the following tutorials to view and set reasonable miner fees. ### How to set Gas Fee in O3 cross-chain wallet? O3 cross-chain wallet currently supports two Gas fee settings for Ethereum networks, one legacy and one EIP-1559. #### Legacy： Gas Fee = Gas Price \* Gas
Gas settings under Legacy can be viewed in this article: {% content-ref url="/pages/q481QHFiz6KjBnJayiHS" %} [What is Gas?](/guides/manage-your-crypto-assets/what-is-gas) {% endcontent-ref %} #### EIP-1559： Gas Fee=（BaseFee + MaxPriorityFee）\*Gas
**Open the O3 cross-chain wallet and go to \[Me]-->\[General Settings] to enable the EIP-1559 fee mode, and the original miner mode is no longer supported.** In the EIP-1559 fee mode, gas fees display a fee range in which the actual miner fee will be incurred. Click on the Gas Fee to enter the settings page of Gas Fee, we support both \[Standard] and \[Customize] settings. **Standard：** The O3 cross-chain wallet offers three Gas Fee options: "Fast", "Best", and "Slow". You can choose one according to your transfer needs. **Customize：** To change the Gas Fee, click \[Customize] to set the parameters of Max Priority Fee, Max Fee, and Gas Limit. {% hint style="info" %} Gas limit is the maximum amount of gas units that the transaction may be able to consume, which is usually fixed at 21000, if you want to modify it yourself, it is not recommended to be lower than 21000. {% endhint %} **In addition, make sure that the Max Fee ≥ Base Fee + Max Priority Fee when setting,** if the Base Fee + Max Priority Fee exceeds the Max Fee, the higher tip will be refunded to the users. You can wait for the transaction to complete or go to the transaction history of an Ethereum block explorer such as Etherscan to view "effectiveGasPrice". **Can I not pay the Priority Fee?** Yes. But the Priority Fee is used to motivate miners to package the transaction, thus it will take you a long time to complete the transaction or may not be completed. And the Priority Fee you paid will not be refunded once you do not pay or the Max Priority Fee paid is not enough to be on the chain. # What is Data？ O3 cross-chain wallet allows users to record custom data which will be stored permanently on the blockchain. ### Steps: 1. Select the asset you want to transfer on the wallet homepage; 2. Click \[Send]; 3. Selec \[Advanced] at the bottom of the transfer page; 4. Click \[Plain] and enter the custom data page; 5. Enter the information you would like to be permanently stored on the block chain, such as "O3". # How to collect dApps？ **Open the O3 cross-chain wallet and click \[Discover] at the bottom menu bar to enter the dApp page.** In the dApp list, O3 supports the top hot dApps of each network, and due to the large number of dApps in the entire list, you need to slide the networks, then you can manage them through the \[Favorites] function if you use Dapps frequently . #### Take O3 Interchange under BNB Chain as an example: 1.BNB Chain→O3 Interchange, click to connect to your wallet; 2.Click the three dots in the upper right corner of the dApp page (As shown below) 3.Click the \[Collect] icon.
**After completing the above operations, return to \[Discover] and you will find that the O3 Interchange you just collected has been displayed in the \[Favorites] column.** The Collection feature is only available for the dApps we have on the shelves, and if you want to cancel the collection, you can follow the steps above to manage it. In addition to the dApps we support, you can also search through the search box under Banner on the dApp page. Enter the dApp name or dApp URL in the search box, select the dApp you want to access based on the search display, and approve to visit. Apart from the favorites and search functions, we also regularly recommend popular and latest dApps at the top of the favorites list column for everyone to understand and participate in. # Swap Handheld Cross-Chain DEX Aggregator. Asset Management, Swap, Bridge, Gas Station... All in O3 cross-chain wallet! {% content-ref url="/pages/pgVil44qoIxOkrZ9W2Rn" %} [How do I cross chain in O3 cross-chain wallet?](/guides/swap/how-do-i-cross-chain-in-o3-cross-chain-wallet) {% endcontent-ref %} {% content-ref url="/pages/l0xEpjBypJjBoAqYIHvS" %} [How to check real-time cross-chain progress and historical transactions?](/guides/swap/how-to-check-real-time-cross-chain-progress-and-historical-transactions) {% endcontent-ref %} {% content-ref url="/pages/aUNkrQHeqWqCbOozUcsN" %} [How to set the slippage and transaction time limit?](/guides/swap/how-to-set-the-slippage-and-transaction-time-limit) {% endcontent-ref %} # How do I cross chain in O3 cross-chain wallet? Before you start, please make sure your O3 cross-chain wallet is updated to the latest version (1.2.0). Go to the wallet and find \[Swap]. #### Step 1: Select the source chain, cross-chain assets, enter the number of assets, and select the wallet address. ![](/files/9V5zKA2P8LNPDcMk8qeT) {% hint style="info" %} If you don't want to enter the quantity of cross-chain assets manually, you can choose from the quantity ratio menu provided at the bottom of the page. {% endhint %} #### Step 2: Select the target chain, the assets to be crossed, and the receiving address. {% hint style="info" %} O3 cross-chain wallet supports cross-chain exchange with ***different addresses*****,** i.e. the outgoing address and the receiving address can be different. So remember to backup the private keys of all addresses. {% endhint %} #### Step 3: Click \[RFQ] and double check the cross-chain information in the detail page. Click \[Confirm] after confirming it is correct. ![](/files/eQA5GU0RfDn90dBd1xl4) If this is the first time your wallet address or token of your choice has engaged in cross-chain activity, you will need to "approve" and then click "confirm". #### Step 4: Enter your wallet password to start cross chain transaction. O3 cross-chain wallet ***supports biometric verification***, you can go to \[Detail] - \[Biometric Verification] on the wallet home page to enable Touch ID/ Face ID. ![](/files/hipUAOpmTuUyeIOY6cBh) **Tip:** You will receive two message notifications from O3 cross-chain wallet after you initiate each cross-chain transaction, one notifying the network fee and the other informing the cross-chain success. # How to check real-time cross-chain progress and historical transactions? #### 1. Real-time cross-chain progress inquiry When you initiate a cross-chain transaction, the transaction information will be displayed at the bottom of the \[Swap] page, and you can click it to check the detailed cross-chain progress. ![](/files/Cg0Ss76u0F69yOj5jCla) #### 2. Historical cross-chain records All the cross-chain transactions made in O3 cross-chain wallet will be displayed in \[Recent Transactions] in the upper right corner of \[Swap] page. ![](/files/8PvNyNMgQhAvHjVwcvxe) **Note:** If you do not delete the wallet, all the cross-chain transactions corresponding to that address will be displayed in the transaction list. # How to set the slippage and transaction time limit? Click the ***\[Settings]*** button to open the settings and select a recommended slippage, or enter the slippage you think is appropriate in the "Custom" box. The default time limit on the source chain is 10 minutes and can be customized. After the time limit runs out, the transaction is terminated and the funds will be returned to the original address. ![](/files/6Sse2DMZBAveQj0zpYyx) # Wallet Q\&A ### What are EVM-Compatible Blockchains? EVM stands for Ethereum Virtual Machine. A virtual machine is created by software to emulate a personal computer. Virtual machine has the same software and hardware computing power from the physical computer it emulated from. All of our daily operations can be executed on this brand new and stand-alone virtual system, such as installing, running software, and storing data. The Ethereum Virtual Machine is a virtual machine built upon the Ethereum blockchain. Programs can be executed without interference and separated from the main chain. Developers can conveniently and readily deploy Ethereum chain smart contracts onto a EVM-compatible blockchain instead of writing codes for the smart contracts from the very beginning. Compared with the Ethereum blockchain, EVM-compatible blockchains have lower gas fee, faster settlement and transaction speed with the same format of contract address starting with 0x. ### What Happens if I Transfer to a Wrong Address? Once the blockchain confirms a transaction, it cannot be canceled or recalled. You can only contact the receipt to return the asset. If you accidentally transferred assets to a wrong address, the only way for you to possibly recover your asset is to find the owner of the address. **Thus, please find out the owner of the recipient's address and try to recover using the following options：** * If the recipient’s address is your address on another platform, please contact the platform’s staff; * If the recipient’s address belongs to your friend, please explain to your friend what happened; * If the recipient’s address is a token's contract address, please contact the developer of the token and ask if they can return your asset. ### When you Import a Wallet, Systems Shows Private keys/Mnemonic Phrases are Wrong #### Mnemonic Phrases are Wrong: * Wrong order: the mnemonic phrases are composed of several words. It’s important to enter them in the correct order when you import a wallet. * Spelling error: misspelling can lead to failure when importing a wallet. Spelling needs to be double-checked. * Incomplete mnemonic phrases: Mnemonic phrases typically contain twelve words. Please make sure all the correct words are entered. * No spaces between mnemonic phrases: When you enter the mnemonic phrases, there should be spaces between words. #### Private Key: * Incomplete private key: private key is a combination of 64 numbers and letters. Please double check when you enter them. * Mixing up capital/non-capital letters with numbers: it is possible to mix up letters with numbers because the private key contains look-alike letters and numbers,. The most frequent mix-ups are : 0 with O, 1 with I, 6 with b, K with k. {% hint style="info" %} Note: there is no letter O in any private key. {% endhint %} ### No Asset Found in the Wallet After Importing a Wallet #### Wallet Address Changes After Import If you find the wallet address changes after importing a wallet, please check if you have backed up multiple private keys or mnemonic phrases. Each set of private key and mnemonic phrases should only match with one address. Please find the correct private key/mnemonic phrases and import again. #### No Asset Found in the Wallet after Importing a Wallet If you don’t see your assets after importing a wallet, please check if the imported wallet address is the same as your previous wallet address. If no discrepancy was found, you can try to search for your token manually in the search bar. If there’s discrepancy in the two addresses, you most likely entered the wrong private key/mnemonic phrases. **Please consider the following two scenarios when troubleshooting:** * Please check if you backed up multiple private keys/mnemonic phrases. Each set of private key and mnemonic phrases should only match with one address. Please find the correct mnemonic phrases/private key and reenter. * Please check if you have entered the wrong private key/mnemonic phrases and generated a wrong address. Please double check and make sure everything is correct before importing your wallet. ### The Password is Wrong/Cannot be Found, How to Recover? If your password is wrong or cannot be found ,you can reset the wallet password by importing the private key/mnemonic phrases. ### The transfer was Successful but the Other Party did not Receive the Assets. * If the recipient’s address is a wallet address, please make sure the address was entered correctly. * If the address is correct, you may check the progress through the corresponding blockchain browser. If the blockchain browser confirms the transfer was successful, please contact the corresponding wallet’s support team. * If the recipient’s address is a trading platform, you might need to wait for the platform to review the legitimacy of the transfer before the funds arrive. If the review takes too long, you can contact the support team at the trading platform for resolution. ### If I Have Other Questions, Who do I Contact? You can reach us at our official email ().