developer tools · no sign-up · open source-grade UX
Your everyday
dev toolbox.
90 fast, private utilities that run entirely in your browser. Format, convert, encode, hash and generate — nothing is ever uploaded.
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90 tools· 100% client-side· opens in <100ms· works offline
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Formatters
Converters
- Number Base Converter Convert between binary, octal, decimal and hexadecimal.
- JSON ↔ YAML Converter Convert JSON to YAML and YAML to JSON.
- JSON ↔ CSV Converter Convert a JSON array of objects to CSV and back.
- Roman Numeral Converter Convert numbers to Roman numerals and back.
- Text ↔ Binary Converter Convert text to binary and binary back to text.
- JSON → TypeScript Generate a TypeScript interface from a JSON object.
- JSON → Go Struct Generate a Go struct (with json tags) from a JSON object.
- CSV → Markdown Table Turn CSV into a Markdown table.
- Query String ↔ JSON Parse a URL query string to JSON and back.
- CSV → SQL Inserts Turn CSV rows into SQL INSERT statements.
- JSON ↔ TOML Converter Convert JSON to TOML and TOML to JSON.
- HTML → Markdown Convert HTML into clean Markdown.
- Temperature Converter Convert between Celsius, Fahrenheit and Kelvin.
Encoders & Decoders
- Base64 Encode / Decode Encode or decode Base64 — UTF-8 safe, in your browser.
- URL Encode / Decode Percent-encode or decode URLs and query strings.
- HTML Entity Encode / Decode Escape or unescape HTML entities (named, decimal and hex).
- JWT Decoder Decode and inspect a JSON Web Token — without uploading it.
- String Escape / Unescape Escape or unescape strings for JSON, JS and more.
- Base32 Encode / Decode Encode or decode Base32 (RFC 4648).
- Basic Auth Header Generator Build or decode an HTTP Basic Authorization header.
- Unicode Escape Converter Convert text to \uXXXX escapes and back.
- Morse Code Translator Translate text to Morse code and back.
- Base58 Encode / Decode Encode or decode Base58 (Bitcoin alphabet).
- Hex ↔ Text Converter Convert text to hex bytes and hex back to text.
- ROT13 Encoder Apply the ROT13 letter substitution cipher.
- Caesar Cipher Shift letters by any amount (encode or decode).
Generators
- UUID Generator Generate v4 (random) or v7 (time-ordered) UUIDs in bulk.
- Lorem Ipsum Generator Generate placeholder text by words, sentences or paragraphs.
- Password Generator Generate strong, random passwords — in your browser.
- ULID Generator Generate sortable, time-ordered ULIDs.
- QR Code Generator Turn text or a URL into a downloadable QR code.
- NanoID Generator Generate compact, URL-safe NanoIDs.
Crypto & Security
- Hash Generator SHA-1, SHA-256, SHA-384 and SHA-512 — computed in your browser.
- HMAC Generator Compute an HMAC (SHA-1/256/384/512) with a secret key.
- AES Encrypt / Decrypt AES-256-GCM encrypt/decrypt with a passphrase — in your browser.
- TOTP / 2FA Code Generator Generate a time-based one-time password from a secret.
- RSA Key Pair Generator Generate a 2048-bit RSA key pair (PEM) in your browser.
- JWT Signer (HS256) Sign a JWT with HS256 and a secret — in your browser.
- Bcrypt Hash & Verify Hash a password with bcrypt, or verify one — in your browser.
- JWT Verify (HS256) Verify a JWT's HS256 signature with a secret.
Text
- Case Converter Convert between camelCase, snake_case, kebab-case, Title Case and more.
- Slugify Turn any text into a clean, URL-safe slug.
- Text Diff Compare two blocks of text and see what changed.
- Regex Tester Test a regular expression and see live matches and groups.
- Word & Character Counter Count characters, words and lines in your text.
- Sort / Dedupe Lines Sort, reverse or remove duplicate lines.
- Whitespace Cleaner Trim, collapse or strip whitespace from text.
- Text Reverser Reverse text by characters, words or lines.
- Word Frequency Counter Count how often each word appears in your text.
- Markdown TOC Generator Generate a table of contents from Markdown headings.
- Regex Escaper Escape special characters for use in a regex.
- Find & Replace Find and replace text, with optional regex.
Web & Frontend
- Color Converter Convert colors between HEX, RGB and HSL.
- Color Contrast Checker Check WCAG color contrast between text and background.
- CSS px ↔ rem Converter Convert between px and rem (16px base).
- CSS Gradient Generator Build a CSS linear gradient with a live preview.
- CSS Box-Shadow Generator Build a CSS box-shadow with a live preview.
- CSS Minifier Strip comments and whitespace from CSS.
- URL Parser Break a URL into protocol, host, path, query and hash.
- Color Shades Generator Generate tints and shades from a base color.
- CSS clip-path Generator Pick a shape and get the CSS clip-path, with a live preview.
- Aspect Ratio Calculator Compute the aspect ratio from width × height.
Data & Dev
- HTTP Status Code Lookup Look up what an HTTP status code means.
- Luhn / Card Validator Validate a credit-card number (or any Luhn number).
- Bytes / Data Size Converter Humanize a byte count, or parse a size back to bytes.
- Email Validator Check whether a string is a well-formed email address.
- JSONPath Evaluator Query a JSON document with JSONPath.
- MIME Type Lookup Look up a MIME type from an extension (and back).
- User-Agent Parser Identify browser, OS and device from a User-Agent string.
- JSON Diff Compare two JSON documents and see what changed.
- JSON Schema Validator Validate a JSON document against a JSON Schema.