> For the complete documentation index, see [llms.txt](https://docs.axonum.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.axonum.io/builders/solidity-compatibility.md).

# Solidity Compatibility

## AI Precompile Differences

Learn how to [deploy on AI EVM](/builders/deploy-on-ai-evm.md).

## EVM/Opcode Differences

Most smart contracts will work on Axonum without any changes. Check out the [Differences From Ethereum page](/chain/differences.md) for a detailed list of the few differences you should know about.

## Gas Differences

Axonum uses the same gas costs as Ethereum. However, Axonum also charges an [L1 Data Fee](https://docs.optimism.io/stack/transactions/fees#l1-data-fee) for the cost of publishing an L2 transaction to L1. This fee is charged based on the size of a transaction in bytes. As a result, smart contract optimization techniques can differ slightly on Axonum. Refer to the [Contract Optimization guide](https://docs.optimism.io/builders/app-developers/contracts/optimization) for more information.