Revert Reason Decoder

Decode Ethereum transaction revert reasons and error messages

Input Method

Revert Data (Hex)

Common Error Selectors

0x08c379a0Error

Error(string)

0x4e487b71Panic

Panic(uint256)

Panic Codes Reference

0x00Generic panic

0x01Assert failed

0x11Arithmetic overflow/underflow

0x12Division or modulo by zero

0x21Invalid enum value

0x22Invalid storage byte array access

0x31Pop on empty array

0x32Array index out of bounds

0x41Out of memory

0x51Invalid internal function call

Error Types: Solidity has three main error types:

require(): Returns Error(string) with custom message
revert CustomError(): Custom errors with parameters (more gas efficient)
Panic: System errors like overflow, divide by zero, array bounds

1. What are Revert Reasons?

When a transaction fails on Ethereum, it reverts with an error message. This error is encoded as hex data. Common error types include require() messages, custom errors, and panic codes from system failures.

2. How does it work?

Error Types

require() errors return Error(string) with a message. Custom errors are more gas-efficient but need the ABI to decode. Panic errors indicate system failures like overflow, division by zero, or array bounds violations.

3. Examples

Require Message - Insufficient Balance

0x08c379a000000000000000000000000000000000000000000000000000000000
→ 'Insufficient token balance' (Uniswap router revert)

Panic Code 0x11 - Arithmetic Overflow

0x4e487b710000000000000000000000000000000000000000000000000000000000
→ Arithmetic overflow/underflow (Compound example)

Custom Error - InsufficientLiquidity

0x0901f85f → Custom error selector (Uniswap V3)
Requires contract ABI to decode parameters

Actual Failed TX Example

TX: 0x123abc...
→ Extract revert data from block explorer and decode