Contract Size Limits

Increase the maximum contract bytecode size beyond Ethereum's 24KB limit.

Overview

Ethereum limits contract size to 24,576 bytes (24KB) via EIP-170. ev-reth allows increasing this limit for use cases requiring larger contracts:

• Complex DeFi protocols
• On-chain game logic
• ZK verification contracts

Configuration

In your chainspec (genesis.json):

{
  "config": {
    "evolve": {
      "contractSizeLimit": 49152
    }
  }
}

Field	Description	Default
contractSizeLimit	Max bytecode size in bytes	24576 (24KB)

Common Values

Size	Bytes	Use Case
24KB	24576	Ethereum default
48KB	49152	2x limit
64KB	65536	2.67x limit
128KB	131072	Large contracts

Trade-offs

Pros:

• Deploy larger, more complex contracts
• Avoid splitting logic across multiple contracts
• Simpler contract architecture

Cons:

• Higher deployment gas costs
• Longer deployment times
• May impact block gas limits

Example

Allow contracts up to 64KB:

{
  "config": {
    "chainId": 1337,
    "evolve": {
      "contractSizeLimit": 65536
    }
  }
}

Considerations

• This is a chain-wide setting—affects all deployments
• Existing tooling may warn about large contracts
• Consider gas costs for deployment and interaction