Developer tools

Free wei to ETH converter. Paste any wei value and get the exact ether amount instantly, in your browser. No API key, no signup, no network calls.

Free ETH to wei converter. Enter any ether amount and get the exact wei value instantly in your browser. No API key, no signup, no network calls.

Free gwei to ETH converter. Enter any gwei value and get the exact ether amount instantly in your browser. No API key, no signup, no network calls.

Free ETH to gwei converter. Enter any ether amount and get the exact gwei value instantly in your browser. No API key, no signup, no network calls.

Free gwei to wei converter. Enter any gwei value and get the exact wei amount instantly in your browser. No API key, no signup, no network calls.

Free wei to gwei converter. Enter any wei value and get the exact gwei amount instantly in your browser. No API key, no signup, no network calls.

Free Ethereum unit converter for wei, gwei and ether. Enter one value and see all units at once, instantly in your browser. No API key, no signup, no network.

Free satoshi to BTC converter. Enter any satoshi value and get the exact bitcoin amount instantly in your browser. No API key, no signup, no network calls.

Free BTC to satoshi converter. Enter any bitcoin amount and get the exact satoshi value instantly in your browser. No API key, no signup, no network calls.

Free Bitcoin unit converter for BTC and satoshi. Enter one value and see the others instantly in your browser. No API key, no signup, no network calls.

Free sun to TRX converter. Enter any sun value and get the exact TRX amount instantly in your browser. No API key, no signup, no network calls.

Free TRX to sun converter. Enter any TRX amount and get the exact sun value instantly in your browser. No API key, no signup, no network calls.

Free TRON unit converter for TRX and sun. Enter one value and see the other instantly in your browser. No API key, no signup, no network calls.

Free nanoton to TON converter. Enter any nanoton value and get the exact TON amount instantly in your browser. No API key, no signup, no network calls.

Free TON to nanoton converter. Enter any TON amount and get the exact nanoton value instantly in your browser. No API key, no signup, no network calls.

Convert hexadecimal to decimal in your browser. Turn 0x-prefixed EVM RPC values like block numbers, gas and wei balances into readable base-10 integers.

Convert decimal integers to 0x-prefixed hexadecimal in your browser. Encode block numbers, gas limits and quantities the way EVM JSON-RPC expects them.

Convert hexadecimal to binary in your browser. Inspect bit patterns in EVM calldata, event topics and packed flags without any API key or network call.

Convert binary to decimal in your browser. Turn bit patterns from packed EVM words and flags back into readable base-10 integers with no key or network call.

Decode hexadecimal bytes to UTF-8 text in your browser. Reveal human-readable strings hidden in EVM calldata, transaction memos and off-chain payloads.

Encode UTF-8 text to hexadecimal bytes in your browser. Prepare string arguments and memos for EVM calldata and off-chain payloads with no key or network call.

Encode text to Base64 in your browser. Prepare compact payloads, memos and metadata that show up alongside off-chain and calldata references. No key, no network.

Decode Base64 to text in your browser. Read memos, metadata and off-chain payloads that arrive Base64-encoded alongside EVM transactions. No key, no network call.

Convert a string to hexadecimal bytes in your browser. Turn text into the hex byte form used in EVM calldata, memos and off-chain payloads. No key, no network.

Convert Unix timestamps to and from human dates in your browser. Read EVM block timestamps, which are Unix seconds, without any API key or network call.

Convert a Unix timestamp to a human-readable UTC date in your browser. Turn EVM block timestamps in seconds into calendar dates. No API key, no network call.

Convert a calendar date to a Unix timestamp in your browser. Produce the Unix seconds value used by EVM block timestamps and contract deadlines. No key, no network.

Calculate an Ethereum gas fee in your browser: gas units times gas price in gwei gives the fee in ETH. Add an ETH/USD price for a dollar estimate. No network call.

Estimate an EVM transaction fee in your browser from gas units and gas price in gwei, with an optional ETH/USD price for dollars. Fully offline, no network call.

Convert a gas price in gwei to a dollar cost in your browser. Combine gas units, gwei and a manual ETH/USD price to see a fee in USD. No network call, no key.

Canonical chain IDs for the major EVM networks, plus how chainId is used in EIP-155 replay protection when signing and broadcasting transactions.

A quick reference for the common Ethereum eth_* JSON-RPC methods — what each call returns, from eth_blockNumber and eth_getBalance to eth_getLogs and eth_call.

The standard JSON-RPC 2.0 error codes — parse error, invalid request, method not found, invalid params, internal error — plus the server-defined -32000 range.

The ERC-20 token standard interface — name, symbol, decimals, totalSupply, balanceOf, transfer, approve, allowance, transferFrom — plus Transfer and Approval events.

The ERC-721 non-fungible token interface — balanceOf, ownerOf, safeTransferFrom, approve, setApprovalForAll, getApproved, isApprovedForAll — plus events and tokenURI.

How Ethereum addresses are structured — 20 bytes, 0x-prefixed, 40 hex chars — how they derive from the public key with keccak-256, and the EIP-55 checksum.

The Bitcoin address types — legacy P2PKH (1), P2SH (3), native SegWit Bech32 (bc1q) and Taproot Bech32m (bc1p) — with their prefixes and testnet equivalents.

How TRON meters transactions with Energy and Bandwidth, how staking or freezing TRX earns those resources, and the base58check T-prefixed address format.

The full Ethereum unit ladder from wei to ether — wei, kwei, mwei, gwei, szabo, finney, ether — with the exact power-of-ten relationships between each.

Decimal places for common assets — ETH 18, BTC 8, TRX 6, TON 9, USDT 6, USDC 6, WBTC 8, DAI 18 — and why decimals matters when reading balanceOf.

How EIP-1559 fees work — a burned base fee that adjusts per block with congestion, a priority-fee tip to the validator, the max fee cap, and the effective gas price.

Common Bitcoin Script opcodes — OP_DUP, OP_HASH160, OP_EQUALVERIFY, OP_CHECKSIG, OP_RETURN, OP_CHECKMULTISIG — and the standard P2PKH locking script pattern.

The two TON address forms — raw workchain:hex and user-friendly base64url — plus the bounceable, non-bounceable and testnet flags encoded in the friendly form.

Base-unit ladders side by side — ETH wei/gwei/ether, BTC satoshi/BTC, TRON sun/TRX, TON nanoton/TON — so you can read raw on-chain integer amounts correctly.

How Ethereum event logs are structured — topics[0] as the event signature hash, indexed params in topics[1..3], non-indexed data — and how eth_getLogs filters them.

When a chain speaks JSON-RPC (EVM, Bitcoin Core) via a POST envelope versus REST (TRON /wallet/*, TON typed paths), and how 1st Node exposes both under one key.

Typical gas costs on Ethereum — the exact 21,000 for a plain ETH transfer, and approximate ranges for ERC-20 transfers, NFT mints and swaps (values labeled approximate).

How to read API HTTP status codes — 200 ok, 400 bad request, 401 bad key, 402/429 for credit and rate limits, 5xx server — plus caching and back-off guidance.