> For the complete documentation index, see [llms.txt](https://docs.altura.com/altura-documentation/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.altura.com/altura-documentation/getting-started/blockchains-and-gas-fees.md).

# Blockchains & Gas Fees

### Blockchains Supported by Altura

Altura supports twelve mainnet blockchains:  

* Ethereum
* Polygon
* Polygon zkEVM
* Binance Smart Chain
* Avalanche-C
* Cronos
* Fantom
* Telos EVM
* Arbitrum
* Optimism
* Base
* Homeverse
* Core DAO

 Each blockchain has unique features and benefits, so it's important to consider which blockchain is best suited for your game or project.

Altura also supports four testnets: Binance Smart Chain Testnet, Polygon Mumbai Testnet, Sepolia Ethereum Testnet.

### Switching Blockchains 

When minting NFTs or a collection on the Altura marketplace, you can specify the blockchain via the dropdown menu in the navigation bar. It's important to note that once an NFT is minted on a specific blockchain, it is bound to that chain and cannot be transferred to a different one. When using Altura's API or SDKs, you don't need to specify the blockchain your NFTs reside on, as Altura will automatically detect this.

<figure><img src="/files/zV7f4PMbTcEdJukA00p1" alt=""><figcaption><p>Network selector on the Altura marketplace</p></figcaption></figure>

### Gas Fees

Gas fees are the fees paid to miners to process transactions on a blockchain. Gas fees are paid in the native currency of the blockchain, such as Ether for Ethereum or BNB for Binance Smart Chain. Gas fees are a crucial component of any blockchain transaction and are necessary to ensure that transactions are processed in a timely manner.

Additionally, if you're just starting out and want to test your game or application on a blockchain without incurring real gas fees, you can use a faucet to obtain gas on our testnet chains. This will allow you to interact with the blockchain and test your application without spending real funds.

{% embed url="<https://sepoliafaucet.com/>" %}

{% embed url="<https://mumbaifaucet.com/>" %}

{% embed url="<https://goerlifaucet.com/>" %}

{% embed url="<https://faucet.quicknode.com/binance-smart-chain/bnb-testnet>" %}