Инструменты разработчика
Бесплатные утилиты без регистрации, работают прямо в браузере — конвертеры единиц, кодировщики, расчёт времени и газа, справочники по RPC.
Unit converters
Wei to ETH converter
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.
ETH to wei converter
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.
Gwei to ETH converter
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.
ETH to gwei converter
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.
Gwei to wei converter
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.
Wei to gwei converter
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.
Ethereum unit converter
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.
Satoshi to BTC converter
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.
BTC to satoshi converter
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.
Bitcoin unit converter
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.
Sun to TRX converter
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.
TRX to sun converter
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.
TRON unit converter
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.
Nanoton to TON converter
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.
TON to nanoton converter
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.
Number bases
Hex to Decimal Converter
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.
Decimal to Hex Converter
Convert decimal integers to 0x-prefixed hexadecimal in your browser. Encode block numbers, gas limits and quantities the way EVM JSON-RPC expects them.
Hex to Binary Converter
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.
Binary to Decimal Converter
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.
Encoding
Hex to UTF-8 Converter
Decode hexadecimal bytes to UTF-8 text in your browser. Reveal human-readable strings hidden in EVM calldata, transaction memos and off-chain payloads.
UTF-8 to Hex Converter
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.
Base64 Encode
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.
Base64 Decode
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.
String to Hex Converter
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.
Time
Unix Timestamp Converter
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.
Unix Timestamp to Date
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.
Date to Unix Timestamp
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.
Gas & fees
Ethereum Gas Fee Calculator
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.
Transaction Fee Calculator
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.
Gwei to USD Converter
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.
Reference
EVM Chain ID List — Ethereum, Base, Arbitrum, Polygon & More
docsCanonical chain IDs for the major EVM networks, plus how chainId is used in EIP-155 replay protection when signing and broadcasting transactions.
Ethereum JSON-RPC Methods — Common eth_* Calls Reference
docsA 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.
JSON-RPC 2.0 Error Codes — Standard Codes Reference
docsThe standard JSON-RPC 2.0 error codes — parse error, invalid request, method not found, invalid params, internal error — plus the server-defined -32000 range.
ERC-20 Interface Reference — Functions & Events
docsThe ERC-20 token standard interface — name, symbol, decimals, totalSupply, balanceOf, transfer, approve, allowance, transferFrom — plus Transfer and Approval events.
ERC-721 Interface Reference — NFT Functions & Events
docsThe ERC-721 non-fungible token interface — balanceOf, ownerOf, safeTransferFrom, approve, setApprovalForAll, getApproved, isApprovedForAll — plus events and tokenURI.
Ethereum Address Format — 20-Byte Hex & EIP-55 Checksum
docsHow 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.
Bitcoin Address Formats — P2PKH, P2SH, Bech32 & Taproot
docsThe Bitcoin address types — legacy P2PKH (1), P2SH (3), native SegWit Bech32 (bc1q) and Taproot Bech32m (bc1p) — with their prefixes and testnet equivalents.
TRON Resource Model — Energy, Bandwidth & Staking TRX
docsHow TRON meters transactions with Energy and Bandwidth, how staking or freezing TRX earns those resources, and the base58check T-prefixed address format.
Wei, Gwei, Ether — Ethereum Unit Ladder Reference
docsThe full Ethereum unit ladder from wei to ether — wei, kwei, mwei, gwei, szabo, finney, ether — with the exact power-of-ten relationships between each.
Common Token Decimals — ETH, BTC, USDT, USDC & More
docsDecimal 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.
EIP-1559 Fee Model — Base Fee, Priority Fee & Max Fee
docsHow 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.
Bitcoin Script Opcodes — Common Opcodes & P2PKH Pattern
docsCommon Bitcoin Script opcodes — OP_DUP, OP_HASH160, OP_EQUALVERIFY, OP_CHECKSIG, OP_RETURN, OP_CHECKMULTISIG — and the standard P2PKH locking script pattern.
TON Address Formats — Raw vs User-Friendly Base64url
docsThe two TON address forms — raw workchain:hex and user-friendly base64url — plus the bounceable, non-bounceable and testnet flags encoded in the friendly form.
Crypto Unit Reference — ETH, BTC, TRON & TON Base Units
docsBase-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.
Ethereum Event Log Anatomy — Topics, Data & eth_getLogs
docsHow 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.
RPC vs REST Cheatsheet — JSON-RPC & REST Across Chains
docsWhen 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.
Ethereum Gas Limits Reference — Transfer, Token & Swap Costs
docsTypical 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).
HTTP Status & Rate Limits — API Response Codes Reference
docsHow 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.