Tools for developers
Format, decode, hash, diff. The everyday utilities you would otherwise paste into a random site — except these never send your code anywhere.
64 tools · all client-side
JSON
All json tools →- JSON Diff & ComparatorCompare two JSON objects or arrays and find semantic differences: added, removed, and modified keys or values.
- JSON FormatterFormat, validate and repair JSON — it tells you what is wrong, then fixes it and says what it changed.
- JSON to YAML ConverterConvert JSON data to clean, idiomatic YAML with custom indentation, quote handling, and array styles.
Text
All text tools →- ASCII Art & Banner GeneratorGenerate stylish ASCII text banners and character art for source code headers, README files, and CLI terminal splash screens.
- CSS Box Shadow GeneratorGenerate smooth multi-layered CSS box-shadows, elevation presets, and Tailwind classes.
- CSS Formatter & MinifierFormat, beautify, or minify CSS stylesheets. Supports custom indent size, line breaks, and comment cleaning.
- HTML Formatter & MinifierBeautify messy HTML with custom indentation or minify it into a single clean line.
- Sort & Deduplicate LinesAlphabetically, numerically, or by length sort lines of text, deduplicate entries, trim whitespace, and reverse order.
- Regex Tester & MatcherTest regular expressions against text. Inspect capture groups, named captures, match indices, and replace strings.
- URL Slug GeneratorConvert article titles and strings into clean, SEO-friendly URL slugs. Handles diacritics removal, custom separators, and special symbol stripping.
- String Escaper & UnescaperEscape and unescape strings across multiple programming languages and serialization formats: JSON, JavaScript, Java, Python, SQL, and CSV.
- Text Case ConverterConvert strings between camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE, Title Case, and more.
- Text Diff CheckerCompare two texts side-by-side or line-by-line. Highlights additions, deletions, modifications, and unified diff output.
- Markdown to HTML ConverterConvert Markdown text to clean HTML in real-time. Supports headings, lists, tables, blockquotes, code blocks, links, and text formatting.
Encoding
All encoding tools →- Base32 ConverterEncode and decode Base32 strings based on RFC 4648 and Crockford specifications used in TOTP 2FA, DNSSEC, and human-readable IDs.
- Base58 ConverterEncode and decode Base58 strings commonly used in Bitcoin, IPFS, and decentralized identifiers.
- Base64 ConverterEncode and decode text to and from Base64. Supports UTF-8 Unicode, URL-safe Base64, and padding control.
- Binary ConverterConvert text to binary (0s and 1s) and binary back to text. Supports custom byte delimiters, 8-bit alignment, and prefix formats.
- Hex ConverterConvert text to hexadecimal and hexadecimal back to text. Supports custom delimiters, case formats, and byte prefixes.
- Hex Dump InspectorGenerate classic Unix hexdump style output with byte offsets, hex representation, and ASCII gutter.
- HTML Entities Encoder / DecoderEscape and unescape HTML entities. Supports named entities (&), decimal (&), and hexadecimal (&) formats.
- Morse Code ConverterEncode text into International Morse Code and decode Morse code dots and dashes back into readable text.
- Unicode ConverterEncode text to Unicode escape sequences (\uXXXX, \u{XXXXX}, U+XXXX) and decode back to human-readable text.
- URL Encoder / DecoderEncode and decode URLs, URI components, and query parameters. Supports full URI and component modes with space-to-plus option.
Crypto
All crypto tools →- BIP-39 Mnemonic & Entropy InspectorInspect, validate, and convert BIP-39 mnemonic phrases (12/15/18/21/24 words) and raw hex entropy with bit-level checksum verification.
- JWT DecoderDecode JSON Web Tokens (JWT) to inspect header and payload claims. Formats standard timestamps (iat, exp, nbf) and checks expiration.
- JWT Sign & GeneratorGenerate and cryptographically sign JSON Web Tokens (JWT) using HMAC (HS256, HS384, HS512) via Web Crypto API.
- Random String GeneratorCryptographically secure random string and token generator with customizable characters and format.
- Hash GeneratorSHA-1, SHA-256, SHA-384 and SHA-512 checksums. Computed by your browser, never sent anywhere.
- HMAC GeneratorCompute Hash-based Message Authentication Codes (HMAC) using SHA-256, SHA-384, SHA-512, or SHA-1 via Web Crypto.
- Password & Secret Token GeneratorGenerate cryptographically secure passwords, API tokens, and passphrases. Includes entropy score, character sets, and ambiguous character filtering.
Time
All time tools →- Cron Expression Parser & Schedule ExplainerParse and explain Cron expressions (minute, hour, day of month, month, day of week) in plain English. Forecast upcoming execution schedules.
- Unix Timestamp ConverterConvert epoch timestamps across seconds, milliseconds, microseconds and ISO dates with timezone and calendar views.
Color
All color tools →Files
All files tools →- Chmod Permissions CalculatorConvert Linux file permissions between Octal (e.g. 755), Symbolic (e.g. -rwxr-xr-x), and command syntax. Includes common presets and umask calculation.
- QR Data TransferMove text or a file between two devices with nothing but a screen and a camera. No network, no pairing, no server.
Data
All data tools →- Bytes & Data Storage Unit ConverterConvert between data storage units: Bytes, KB, MB, GB, TB, PB (decimal / SI 1000) and KiB, MiB, GiB, TiB, PiB (binary / IEC 1024).
- CSV to JSON ConverterConvert CSV and TSV tabular data into structured JSON objects or 2D arrays. Automatically detects types and handles RFC 4180 quotes.
- Docker Compose Validator & InspectorValidate Docker Compose YAML syntax, inspect services, ports, environment variables, and volume topologies.
- JSON to CSV ConverterConvert JSON objects or arrays into standard CSV / TSV spreadsheets. Automatically infers table headers and handles nested structures.
- SemVer Version & Range CheckerCompare semantic versions, validate range rules (^, ~, >=), and calculate next release bumps.
- SQL Formatter & BeautifierFormat, prettify, indent, and uppercase keywords in SQL queries (SELECT, INSERT, UPDATE, DELETE, JOINs, WHERE, GROUP BY).
- User-Agent ParserParse User-Agent strings into browser name and version, OS architecture, rendering engine, and device type.
- XML Formatter & MinifierFormat, pretty-print, indent, and minify XML and HTML documents with configurable indentation and comment handling.
- YAML to JSONParse YAML documents and convert to formatted or minified JSON.
- cURL to Code ConverterConvert cURL command lines into JavaScript fetch, Node.js Axios, or Python requests code.
- Ethereum CREATE2 Deterministic Address CalculatorCalculate deterministic smart contract deployment addresses using EIP-1014 CREATE2 with deployer, salt, and initCode or code hash.
- EVM Bytecode Disassembler & Opcode ReferenceDisassemble raw EVM runtime or creation bytecode into assembly instruction streams with PC offsets, gas costs, and stack diffs.
- IPv4 Subnet & CIDR CalculatorCalculate IPv4 subnet masks, CIDR network ranges, usable host ranges, broadcast addresses, and wildcard masks.
- MAC Address Lookup & FormatterFormat MAC addresses, inspect OUI vendor details, and determine unicast/multicast and global/local scope.
- Merkle Tree & Proof Generator for Airdrops and WhitelistsGenerate standard OpenZeppelin-compatible Merkle Trees, root hashes, and per-leaf cryptographic inclusion proofs from address lists or data values.
- Ethereum RLP (Recursive Length Prefix) Encoder & DecoderEncode arbitrary JSON nested arrays/strings into Ethereum RLP hex bytes, and decode raw RLP byte streams into structured JSON and hierarchical trees.
- Solidity 4-Byte Function Selector Lookup & Keccak-256 CalculatorCalculate 4-byte function selectors from canonical signatures and reverse-lookup raw selectors against built-in ERC standard databases.
- Solana Address & PDA InspectorInspect Solana public keys, check Ed25519 curve membership (wallet vs PDA), decode hex/byte representation, and derive Program Derived Addresses (PDA) & ATAs.
- Solidity ABI & Signature InspectorParse Solidity contract ABI JSON into human-readable interface signatures, event topics, and error definitions.
- Solidity Calldata & EVM Raw Word DissectorDissect EVM transaction calldata into 4-byte method selectors and 32-byte (256-bit) ABI words with address, uint256, and boolean conversions.
- URL Parser & Query InspectorDeconstruct URLs into protocol, host, port, path, hash, and detailed query parameter tables.
Math
All math tools →- Ethereum Unit Converter (Wei, Gwei, Ether)Convert Ethereum denominations (Wei, Kwei, Mwei, Gwei, Szabo, Finney, Ether, Tether) with arbitrary precision BigInt math.
- Number Base ConverterConvert numbers between binary, octal, decimal, hexadecimal, and arbitrary bases (2 to 36). Supports large BigInt precision.
- Programmer CalculatorEvaluate fixed-width integer expressions, switch bases, flip bits and inspect endian, character and two’s-complement views.
Generators
All generators tools →- NanoID GeneratorGenerate URL-friendly, cryptographically secure compact unique string IDs (NanoID) with custom length and alphabet.
- ULID Generator & DecoderGenerate and inspect Universally Unique Lexicographically Sortable Identifiers (ULID). Supports batch generation, case formatting, and timestamp extraction.
- UUID / GUID GeneratorGenerate cryptographically secure UUID v4 and time-ordered UUID v7. Supports batch generation, hyphens, and uppercase formatting.