Blockchain and Ethereum Tools
These tools help smart contract developers, wallet and dapp engineers, and people reviewing on-chain activity read and calculate Ethereum data by hand. Decode a raw signed transaction, match calldata to a contract ABI, work out what a transaction will cost in gas, convert between wei, gwei and ether or between satoshi and bitcoin, and build explorer links for an address, transaction or block.
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All Blockchain Tools (5)
Ethereum Transaction Decoder
Decode raw signed Ethereum transactions (legacy and typed)Smart Contract ABI Decoder
Decode smart contract ABI and function callsGas Fee Calculator
Calculate Ethereum gas fees and transaction costsBlockchain Explorer Links Generator
Generate explorer links for blockchain transactions and addressesCryptocurrency Unit Converter
Convert crypto units (Wei, Gwei, ETH)
Which tool do I need?
See what a signed transaction will do before broadcasting it
Decode the raw hex for recipient, value, fees and chain ID, then decode any unfamiliar calldata against the contract ABI.
Decode the input data of a contract call
Paste the ABI and the calldata into the Smart Contract ABI Decoder. It matches the selector and decodes tuples, arrays and dynamic types.
Estimate what a transaction will cost in ETH and dollars
Enter base fee, priority fee, max fee and gas in the Gas Fee Calculator, plus an ETH price, to see the fee, the burned part and the worst case.
Convert a wei amount from an RPC response into ether
The Cryptocurrency Unit Converter uses integer arithmetic, so 18-digit wei values convert without rounding.
Open an address or transaction on Etherscan or another explorer
Pick the chain and lookup type and the generator builds links for the supported explorers, after checking the format and checksum.
About Blockchain Tools
The decoders chain together. The Ethereum Transaction Decoder unpacks legacy and typed transactions (access-list, EIP-1559, blob and set-code), shows value, fee fields and signature values, and decodes common ERC-20 and ERC-721 calls. Anything else leaves a 4-byte selector and raw calldata, which you paste into the Smart Contract ABI Decoder with the contract's ABI to get named, typed arguments. The gas fields from a decoded transaction go into the Gas Fee Calculator, which works out the burned base fee, the validator tip and the maximum charge in exact wei arithmetic. The Cryptocurrency Unit Converter and the Blockchain Explorer Links Generator handle the routine conversions and lookups around that work.
Everything here runs in the browser with no node, RPC provider or price feed. That makes the tools safe to use with signed transactions, but it sets limits: the transaction decoder cannot fetch a transaction by hash or recover the sender address, the gas calculator uses the base fee and ETH price you type, and the link generator checks address format and EIP-55 checksums but cannot tell whether an address has any activity. Amounts are handled with BigInt so 18-decimal values stay exact, but token amounts still need the token's own decimals applied.
Guides
- Ethereum Units and Gas Fees: Wei, Gwei and EIP-1559 Worked OutWhy ether amounts are integers of wei, how base fee, tip and max fee combine into what you pay, and how to do the maths without floating point mistakes.
- Decoding Ethereum Transactions: RLP, Selectors and ABI CalldataRead a raw signed transaction byte by byte, work out a function selector, decode ABI calldata with dynamic types, and build explorer links that resolve.
- Comparing Hash Algorithms: Security Margins, Speed and the Keccak TrapHow digest size maps to real security, why MD5 and SHA-1 fell, when SHA-512 beats SHA-256, and why a library called SHA3 may not give SHA-3 output.
Frequently asked questions
Do these blockchain tools connect to a node or a wallet?
No. They work entirely on the values you paste or type, with no RPC calls, wallet connection or price feed. That keeps signed transactions and addresses private, and it means anything that needs chain state, such as balances, receipts or the current base fee, has to come from your wallet, a node or an explorer.
Why do Ethereum tools need BigInt instead of normal numbers?
One ether is 10^18 wei, which is far past 2^53, the largest integer a JavaScript number holds exactly. Ordinary numbers round the last digits of wei amounts, so precise tools count in the smallest unit with BigInt and only format to ether for display.
Which chains do the blockchain tools cover?
The transaction, ABI and gas tools work for Ethereum and EVM chains that use the same transaction formats. The explorer link generator covers Ethereum, Bitcoin, Polygon PoS, BNB Smart Chain, Arbitrum One, Base and OP Mainnet. The unit converter handles Ethereum and Bitcoin denominations.
What is the difference between a transaction hash and a raw transaction?
A transaction hash is a 32-byte Keccak-256 identifier of the signed transaction, used to look it up. A raw transaction is the full signed, encoded transaction itself. Only the raw form can be decoded offline; a hash has to be looked up on a node or explorer.