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Contract debugging

Solidity Revert & Custom Error Decoder

Decode standard Solidity Error, Panic, and ABI-defined custom error data locally without executing code.

✓ Runs in your browser✓ No account✓ No wallet signature
Calculated locally

Decode Solidity revert data

Paste the returned 0x data and optionally add one custom error signature per line.

Result

Your manual estimate

Calculated locally
Method

How this calculator works

01

Paste revert hex and optionally add a trusted JSON or human-readable ABI for custom errors.

02

CoinCalcs validates the manual inputs and applies this published model: error selector = first 4 bytes; arguments = ABI-decoded remaining bytes

03

The result is calculated locally in the browser and is not sent to CoinCalcs or a market-data provider.

Formula

The calculation

error selector = first 4 bytes; arguments = ABI-decoded remaining bytes
Example

A concrete scenario

Revert data beginning with 0x08c379a0 can decode to Error(string) and expose the supplied reason text.

Data provenance

Sources used

ViemLocal error-result decodingUser inputsNo live price, wallet, exchange, or protocol request

Privacy: Calculator inputs are processed locally in your browser. CoinCalcs does not receive or store these inputs. Theme and cookie preferences may be stored on this device.

Known limits

What this estimate cannot guarantee

  • Decoded text does not prove contract safety, execution context, or the source of nested revert data.
  • The result is only as current and accurate as the assumptions entered in the form.
  • The output is educational scenario arithmetic, not financial, investment, tax, legal, or security advice.
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FAQ

Questions about this tool

What does the Solidity Revert & Custom Error Decoder calculate?

Decode standard Solidity Error, Panic, and ABI-defined custom error data locally without executing code.

Does the Revert decoder use live market or wallet data?

No. It uses only the values entered in the form and labels the result as a manual estimate.

Are my inputs uploaded or stored?

No. The calculation runs in your browser. CoinCalcs does not receive or retain the form values.

Last reviewed: July 22, 2026