CoinCalcs
Tools
Contract calls

Ethereum ABI Function Encoder

Encode a function call and JSON arguments into EVM calldata locally with a trusted ABI.

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

Encode a function call

Provide one human-readable Solidity function signature and a JSON argument array.

Result

Your manual estimate

Calculated locally
Method

How this calculator works

01

Provide a JSON or human-readable ABI, select the function name, and enter arguments as a JSON array.

02

CoinCalcs validates the manual inputs and applies this published model: calldata = 4-byte function selector + ABI-encoded arguments

03

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

Formula

The calculation

calldata = 4-byte function selector + ABI-encoded arguments
Example

A concrete scenario

Encoding transfer(address,uint256) with a recipient and amount produces calldata beginning with 0xa9059cbb.

Data provenance

Sources used

ViemABI function-data encodingUser 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

  • Correct encoding does not validate the destination contract, token decimals, business intent, or transaction safety.
  • 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.
Continue checking

Related tools

Developer tools

Calldata Decoder

Inspect an EVM function selector and decode parameters locally with an ABI you provide.

Browser onlyNo sign-in
ABI identifiers

EVM Function Selector Generator

Generate the canonical four-byte EVM function selector from a Solidity function signature.

Browser onlyNo sign-in
Calculation methodologyData sources & freshness
FAQ

Questions about this tool

What does the Ethereum ABI Function Encoder calculate?

Encode a function call and JSON arguments into EVM calldata locally with a trusted ABI.

Does the ABI encoder 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