Toolbox app library

Fast, private developer tools that run entirely in your browser. Every tool has its own address and works offline once loaded.

Crypto & Security

Hash Text - MD5, SHA-1, SHA-256, SHA-512 digests
HMAC - Keyed hash message authentication codes
Encrypt / Decrypt - AES-GCM text encryption with a passphrase
Token Generator - Strong random passwords and API tokens
TOTP - Time based one-time passwords from a secret
Basic Auth - Build Authorization headers from credentials
Key Pair - Generate RSA and elliptic curve keys as PEM
Password Strength - Entropy, weaknesses and time to crack
Certificate Decoder - Read an X.509 certificate or signing request
SSH Keys - Generate and inspect OpenSSH keys offline

Converters

Base64 - Encode and decode text or files
Color Converter - HEX, RGB, HSL, OKLCH and contrast checks
Colour Palette - Tailwind style scales, a colour wheel and harmonies
Case Converter - camelCase, snake_case, kebab-case and more
Date & Time - Unix timestamps, ISO 8601 and relative time
Number Base - Binary, octal, decimal, hex and any base
JSON ⇄ YAML - Convert between JSON and YAML documents
Text Encoder - Binary, hex, unicode, NATO, morse and ROT13
List Converter - Sort, dedupe, wrap and rejoin lists
Roman Numerals - Convert numbers to and from Roman numerals
Currency - Convert between currencies with daily rates
Morse Code - Translate text to Morse and play it back
PDF Studio - Merge, split, rotate and convert PDFs

Web

URL Encode - Percent-encode and decode URL components
URL Parser - Break a URL into its parts and query params
HTML Entities - Escape and unescape HTML entities
JWT Parser - Decode and inspect JSON Web Tokens
Keycode Info - Inspect keyboard events key by key
Slugify - Turn any string into a clean URL slug
HTTP Status - Searchable reference of HTTP status codes
Header Review - Grade response headers for security and privacy
Gradient Maker - Build CSS gradients with draggable colour stops
CSS Animation - Keyframe presets with a cubic-bezier editor

Development

JSON Formatter - Format, validate, minify and explore JSON
JSON Diff - Compare two JSON documents key by key
SQL Formatter - Readable formatting for SQL statements
XML Formatter - Indent and minify XML or HTML markup
Crontab - Explain cron expressions and preview next runs
Chmod - Unix permissions in octal and symbolic form
Regex Tester - Test patterns with live matches and groups
CSV Studio - Open, edit and convert CSV data in a table
Mock Data - Generate realistic test data from a field list
JSON Schema - Infer a schema from samples and validate documents
API Spec Editor - Edit and check OpenAPI documents
Docker Compose - Convert docker run commands to compose files
Compose to K8s - Turn a compose file into Kubernetes manifests
Kubernetes - Generate deployment, service and ingress manifests
JSX to SVG - Convert React components to SVG and back

Network

Subnet Calculator - IPv4 CIDR ranges, masks and host counts
IP Converter - IPv4 in decimal, hex, binary and octal
MAC Address - Generate and reformat MAC addresses
DNS Lookup - Dig style record lookups over DNS-over-HTTPS
Speed Test - Measure download, upload, latency and jitter
Domain Lookup - RDAP records for a domain, IP or network
WebSocket Tester - Connect to a socket and watch the frames

Text

Lorem Ipsum - Placeholder copy in words, sentences or lists
Text Stats - Counts, reading time and character analysis
Text Diff - Compare two texts line by line
Markdown - Write markdown and preview the HTML
Emoji Picker - Browse, search and copy emoji with their code points
Unicode Tables - Browse Unicode blocks and inspect any character

Math & Units

Math Evaluator - Evaluate expressions with functions and constants
Unit Converter - Length, mass, data, temperature and time
Function Plotter - Graph expressions with zoom, roots and derivatives
Statistics - Summary, histogram and box plot for a set of numbers

Media

QR Code - Generate scannable QR codes offline
Image Converter - Convert, resize and compress images in the browser
Video & Audio - Transcode video and audio with WebAssembly
Barcode - Code 128, EAN and Code 39 barcodes as SVG
Icon Studio - Build an icon from thousands of parts, or describe one
Favicon Maker - Every icon size, an .ico and the manifest
Exif Metadata - Read and strip metadata from JPEG photos
MP3 Metadata - Edit ID3 tags and artwork on MP3 files
Placeholder SVG - Generate placeholder images as inline SVG
ASCII Art - Text banners and image to ASCII conversion
SVG Studio - View, clean, recolour and export SVG
Voice Recorder - Record audio and transcribe it on this device
Mirror - Camera mirror with an adjustable ring light
Screenshot Studio - Capture, annotate, blur and compare screenshots
Paint - Pencil, shapes, fill and spray on a canvas
Poster Studio - Design posters and social variants with an event QR

Science

Periodic Table - All 118 elements with full properties
Molecule Viewer - Vitamins, drugs and famous molecules in 3D
Circuit Lab - Build and simulate basic electronic circuits
Physics Lab - Balls, blocks, springs, rods, jacks and motors
Logic Lab - Gates, flip-flops, counters, decoders and LED displays
Optics Lab - Lenses, mirrors and prisms with real ray tracing

Local AI

AI Chat - Chat with a model running on this device
AI Code - Explain, review, document and convert code
AI Writer - Summarise, rewrite, translate and proofread
Translate - Translate text with a model on this device
AI Regex - Describe a pattern and get a tested regex

Play

Typing Test - Words per minute, accuracy and trouble keys
Chess - Play the computer, learn the openings and train tactics
Sudoku - Generated puzzles with notes and hints
Blocks - Stack falling pieces and clear lines
Memory - Flip cards and find the matching pairs
Word Guess - Six tries to find the five letter word
Drum Kit - Play pads and build a 16 step beat
Tuner - Tune a guitar, bass or ukulele by ear or mic
MIDI Keyboard - Playable synth with computer keyboard and MIDI input
2048 - Slide and merge tiles to reach 2048
Minesweeper - Clear the grid without hitting a mine
Snake - Eat, grow and do not bite yourself
Breakout - Bounce the ball and clear every brick
Pong - The original paddle duel against the machine
Invaders - Hold the line against descending waves
Solitaire - Klondike patience with draw one or three
T-Rex Run - Jump the cacti in the offline runner

Utility

UUID - Generate v4 and v7 identifiers in bulk
Device Info - Everything the browser knows about this device
Clock - World clocks, stopwatch and countdown timer
Calendar - Month view with events saved per workspace
Portfolio - Track holdings, allocation and profit or loss
Notes - Quick scratch notes saved to this workspace
Tasks - A lightweight checklist per workspace
Time Zones - Line up cities and find the overlapping hours
IBAN Validator - Check bank account numbers and read their parts
Serial Console - Talk to a serial device over USB
Bluetooth - Read, subscribe and write to GATT characteristics
Gamepad Tester - Check every stick, trigger and button
Code Scanner - Read QR codes and bar codes from the camera, a picture or the screen
Tax Calculator - Work out net pay after tax in 23 countries, entirely on your device