EVMTools
Free online tools for Ethereum and cryptocurrency developers. No sign-up required.
EVMTools provides 50 free online tools for developers and crypto builders. Generate QR codes, strong passwords, word counts, SHA-256/Keccak256/MD5 hashes, format JSON, decode JWTs, test regex, compare text diffs, pick colors, generate UUIDs, convert cases, encode URLs, decode ABI calldata, calculate gas fees, and more — all running locally in your browser with no sign-up required. Plus, explore our 33 comprehensive guides covering DeFi, staking, hardware wallets, crypto exchanges, smart contracts, DAOs, oracles, and blockchain basics.
Crypto Tools
Encoding & Conversion
ABI Encoder / Decoder
Encode and decode Ethereum ABI data. Input function signatures and parameters to generate calldata.
Hex / Decimal Converter
Convert between hexadecimal and decimal numbers. Useful for Ethereum block numbers, values, and calldata.
UTF-8 / Hex / Bytes Converter
Convert between UTF-8 text, hexadecimal strings, and byte arrays. Essential for encoding and debugging Ethereum data.
RLP Encoder / Decoder
Encode and decode Recursive Length Prefix (RLP) data. The serialization format used by Ethereum transactions and blocks.
Unix Timestamp Converter
Convert between Unix timestamps and human-readable dates. Includes notable Ethereum timestamps and relative time display.
Base64 Encoder / Decoder
Encode and decode Base64 strings online. Supports text and hex input with URL-safe Base64 option for Ethereum development.
Bytes32 / String Converter
Convert between bytes32 hex, UTF-8 strings, numbers, and addresses. Visualize padding for Solidity bytes32 values.
URL Encoder / Decoder
Encode and decode URL components online. Compare encodeURIComponent vs encodeURI with a common URL encodings reference table.
Hashing & Cryptography
Keccak256 Hash Generator
Generate Keccak256 hashes from text input. The hash function used by Ethereum and Solidity.
SHA-256 Hash Generator
Generate SHA-256 hashes from text or hex input using the Web Crypto API. Compare SHA-256 with Keccak256 for Ethereum development.
MD5 Hash Generator
Generate MD5 hashes from text input online. Pure JavaScript implementation with RFC 1321 test vectors. Note: MD5 is not cryptographically secure.
Batch Keccak256 Hasher
Hash multiple inputs at once with Keccak256. Get hashes and function selectors for multiple function signatures, storage keys, or arbitrary text.
Solidity Event Hash Calculator
Calculate keccak256 hashes for Solidity event signatures. Get topic 0 values for filtering Ethereum logs.
Function Selector Lookup
Calculate Solidity function selectors from signatures using keccak256. Browse a table of 30+ common ERC-20, ERC-721, and Ownable selectors.
EIP-712 Typed Data Hasher
Hash EIP-712 typed structured data online. Compute domain separator, struct hash, and final signing hash for permits and gasless transactions.
Merkle Proof Generator
Generate and verify Merkle proofs for whitelists and allowlists. Build Merkle trees with keccak256 hashing.
Address & Keys
Checksum Address Converter
Convert Ethereum addresses to EIP-55 checksummed format for safe usage in transactions.
Address Validator
Validate cryptocurrency wallet addresses for Ethereum, Bitcoin, and Solana.
Private Key to Address
Derive Ethereum public key and checksummed address from a private key. Shows uncompressed and compressed public keys.
BIP39 Mnemonic Generator
Generate secure BIP39 mnemonic seed phrases (12 or 24 words) for cryptocurrency wallets.
Signature Signer & Verifier
Sign messages with a private key and verify Ethereum EIP-191 signatures. Recover signer addresses from signed messages.
CREATE2 Address Calculator
Calculate deterministic smart contract addresses using CREATE2. Input deployer address, salt, and init code hash to predict deployment addresses.
Smart Contract Analysis
Calldata Decoder
Decode raw Ethereum calldata hex into human-readable function calls and parameters.
Storage Slot Calculator
Calculate Solidity storage slots for variables, mappings, and nested mappings using keccak256.
ERC-20 Token Info Decoder
Decode ERC-20 token function calls and event logs from raw transaction data.
Solidity Error Decoder
Decode Solidity revert data into human-readable error messages. Supports Error(string), Panic(uint256) codes, and custom errors.
Contract Size Calculator
Check if your Solidity contract bytecode fits within the 24KB EIP-170 limit. Paste bytecode to see size, percentage used, and optimization tips.
Gas & Units
ETH Unit Converter
Convert between Ethereum units: Wei, Gwei, and ETH. Essential for gas and transaction calculations.
Gas Fee Calculator
Calculate Ethereum transaction costs from gas limit and gas price. Estimate fees in ETH and USD.
Token Unit Converter
Convert between human-readable token amounts and raw values for any ERC-20 token. Supports custom decimals for USDC, WBTC, ETH, and more.
Ethereum Epoch / Slot Calculator
Convert between Ethereum beacon chain epochs, slots, timestamps, and dates. Live current epoch and slot display with notable epoch references.
Developer Utilities
JSON Formatter / Validator
Format, minify, and validate JSON data online. Pretty-print with configurable indentation and see detailed error positions for invalid JSON.
JWT Decoder
Decode JSON Web Tokens into header, payload, and signature. View claims, check expiration, and validate JWT structure.
UUID Generator
Generate UUID v4 identifiers online. Bulk generate up to 25 UUIDs with options for uppercase, lowercase, and with or without hyphens.
Regex Tester
Test regular expressions with real-time matching, capture group display, and flag toggles. Includes common patterns for email, URL, Ethereum addresses, and more.
Diff Checker
Compare two texts and see the differences highlighted line by line. Online diff tool with added, removed, and unchanged line detection.
Markdown Preview
Write markdown and see a live rendered preview side by side. Supports headers, bold, italic, code blocks, lists, links, and more.
Cron Expression Parser
Parse and explain cron expressions online. Get human-readable descriptions, see next scheduled run times, and learn cron syntax.
Slugify Tool
Convert text to URL-friendly slugs online. Customize separator, case, max length, and handle unicode characters. Free slug generator.
Text & Content Tools
Word Counter
Count words, characters, sentences, and paragraphs instantly. Get reading time estimates, character counts, and word frequency analysis.
Character Counter
Count characters with and without spaces. Check text against Twitter, meta description, and other platform character limits in real time.
Text Case Converter
Convert text between camelCase, PascalCase, snake_case, kebab-case, UPPERCASE, lowercase, Title Case, CONSTANT_CASE, and more.
Lorem Ipsum Generator
Generate lorem ipsum placeholder text by paragraphs, sentences, or words. Free dummy text generator for design and development.
HTML Encoder / Decoder
Encode and decode HTML entities online. Convert special characters to HTML entities for safe display in web pages.
Generators & Converters
Password Generator
Generate strong, random passwords with customizable length, uppercase, lowercase, numbers, and symbols. Cryptographically secure with strength meter.
Color Picker / Converter
Pick colors and convert between HEX, RGB, and HSL formats. Check WCAG contrast ratios, generate shades, and get CSS values.
QR Code Generator
Generate QR codes from text, URLs, emails, or Wi-Fi credentials online. Customize colors, download as PNG. Free, client-side tool.
Image to Base64 Converter
Convert images to Base64 encoded strings online. Drag and drop PNG, JPG, GIF, SVG, or WebP files to get Data URIs for HTML, CSS, and JSON.
JSON to CSV Converter
Convert JSON arrays to CSV and CSV to JSON online. Supports custom delimiters, proper escaping, nested objects, and file download.
Number Base Converter
Convert numbers between binary, octal, decimal, and hexadecimal online. Supports arbitrarily large numbers with BigInt.
Developer Guides
What is Keccak256?
Learn how Keccak256 hashing works, why Ethereum uses it, and how it differs from SHA-3.
ABI Encoding Explained
Understand how Ethereum ABI encoding works, from function selectors to parameter encoding.
How Gas Fees Work
A complete guide to Ethereum gas fees: what they are, how they're calculated, and how to optimize them.
BIP39 Mnemonic Phrases Explained
Learn how BIP39 mnemonic seed phrases work, how they generate keys, and best practices for security.
What is ERC-20?
Learn what ERC-20 tokens are, how the standard works, the 6 required functions, transfer patterns, and common vulnerabilities.
What is ERC-721 (NFTs)?
Learn what ERC-721 is, how NFT smart contracts work, the required interface, metadata standards, and minting.
What is a Smart Contract?
Learn what smart contracts are, how they work on Ethereum, Solidity basics, real-world use cases, and security considerations.
How to Read Etherscan
Learn how to read Etherscan: understand transactions, contracts, event logs, token transfers, and advanced features.
What is DeFi?
Learn what DeFi is, how decentralized finance works, major protocols, AMMs, liquidity pools, and DeFi risks.
What is Staking?
Learn how Ethereum staking works, liquid staking options, validator requirements, staking rewards, and risks.
Ethereum vs Bitcoin
A comprehensive comparison of Ethereum and Bitcoin: consensus, smart contracts, tokenomics, and Layer 2 solutions.
What is a Layer 2?
Understand Layer 2 scaling solutions: optimistic rollups, ZK rollups, and how they reduce Ethereum gas costs.
What is MEV?
Learn about Maximal Extractable Value: frontrunning, sandwich attacks, Flashbots, and how to protect yourself.
EIP-1559 Explained
Understand Ethereum's fee market reform: base fee, priority tips, ETH burn, and how gas pricing works post-London.
What is Web3?
Learn what Web3 is, how it differs from Web1 and Web2, the role of decentralization and blockchain, dApps, wallets, and digital ownership.
What is a Crypto Wallet?
Learn what crypto wallets are, how they work with private and public keys, hot vs cold wallets, security best practices, and how to choose the right wallet.
What is a DAO?
Learn what DAOs are, how decentralized governance works with tokens and voting, famous DAOs, DAO types, tools, and legal considerations.
What is a DEX?
Learn what decentralized exchanges are, how AMMs work, DEX vs CEX comparison, liquidity pools, slippage, price impact, and MEV.
What is Yield Farming?
Learn what yield farming is, how liquidity mining works, APR vs APY, farming strategies, risks, and popular platforms like Yearn and Convex.
What is Impermanent Loss?
Learn what impermanent loss is, the IL formula, real examples with numbers, an IL table by price change, and strategies to mitigate liquidity pool risk.
What is a Flash Loan?
Learn what flash loans are, how atomic transactions work, platforms like Aave, use cases including arbitrage, famous flash loan attacks, and Solidity code examples.
What is a Blockchain Oracle?
Learn what blockchain oracles are, the oracle problem, types of oracles, major providers like Chainlink and Pyth, oracle attacks, and DeFi use cases.
What is a Crypto Bridge?
Learn what cross-chain bridges are, bridge types, major bridges like Wormhole and LayerZero, bridge security risks, and famous bridge hacks.
What is Account Abstraction?
Learn what account abstraction is, how ERC-4337 works, smart contract wallets, social recovery, gas sponsorship, session keys, and wallet implementations.
What is ERC-1155?
Learn what ERC-1155 is, how the multi-token standard works, batch transfers, gas efficiency, and how it compares to ERC-20 and ERC-721.
How to Deploy a Smart Contract
Step-by-step guide to deploying smart contracts using Remix, Hardhat, and Foundry. Covers testnet deployment, Etherscan verification, and mainnet considerations.
What is a Crypto Token?
Learn what crypto tokens are, token vs coin differences, token types (utility, governance, security, stablecoin), token standards, and tokenomics.
What is Ethereum?
Comprehensive Ethereum guide covering history, how it works, The Merge, ETH the asset, the ecosystem (DeFi, NFTs, DAOs, L2s), and the roadmap.
What is a Blockchain?
Beginner-friendly guide to blockchain technology: how blocks are chained, consensus mechanisms, blockchain types, the trilemma, and use cases beyond crypto.
Best Hardware Wallets 2025
Compare the best hardware wallets: Ledger Nano X, Nano S Plus, Trezor Model T, and Safe 3. Prices, features, security, and buying guide.
Best Crypto Exchanges 2025
Compare top crypto exchanges: Binance, Bybit, Coinbase, Kraken, and OKX. Fees, security, features, and recommendations for beginners and advanced traders.
How to Stake ETH (Step-by-Step)
Complete guide to staking Ethereum: solo staking, liquid staking with Lido and Rocket Pool, exchange staking, APR comparison, risks, and tax implications.
Ledger vs Trezor 2025
Detailed Ledger vs Trezor comparison: security architecture, user experience, price, features, controversies, and which to buy for your use case.
MD5 vs SHA-256
Compare MD5 and SHA-256 hash algorithms: speed, security, output size, collision resistance, and real-world use cases.
JSON vs CSV
Compare JSON and CSV data formats: structure, readability, file size, API usage, nested data support, and when to use each.
Base64 vs Hex Encoding
Compare Base64 and hexadecimal encoding: size overhead, character sets, use cases, and when to choose each encoding scheme.
camelCase vs snake_case
Compare camelCase and snake_case naming conventions by language, readability research, conversion rules, and best practices.
UUID vs NanoID
Compare UUID and NanoID: format, collision probability, performance, size, and which unique identifier to use for your project.
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Frequently Asked Questions
What is EVMTools?
EVMTools is a free, open-source collection of online developer tools for Ethereum and EVM-compatible blockchains. All tools run entirely in your browser — no data is sent to any server.
Are these tools safe to use?
Yes. All tools run client-side in your browser. No private keys, seed phrases, or sensitive data is ever transmitted to our servers. The source code is open and auditable.
What blockchains do these tools work with?
Most tools work with any EVM-compatible blockchain including Ethereum, Polygon, Arbitrum, Optimism, Base, BSC, Avalanche, and more.
Do I need to install anything?
No. All tools work directly in your web browser. No downloads, extensions, or sign-ups required.