502+ Free Developer Tools
502+ free developer tools in one place — no ads, no sign-up. Most tools process data locally; network tools use external services.
- Most tools run locally
- No ads, privacy-focused
- Free, no sign-up
Built for development and QA
Identity & Tax Test Data
Generate synthetic identity and bank-number fixtures, then check supported formats and checksums. Generated values do not establish identity or ownership.
National Identity Generator
Synthetic national ID fixtures — TC Kimlik, SSN, Emirates ID, CPF, NRIC and more.
Tax Number Generator
Format-valid tax IDs — VKN, EIN, TFN, Steuernummer, VAT, UEN and more.
IBAN Generator
Generate mock IBANs with ISO 13616 check digits for form validation and payment sandbox tests.
TIN Generator
Choose a tax identifier standard and export synthetic fixtures for onboarding and tax-form tests.
Driver's License Generator
Generate mock license-number fixtures for form validation and QA. No documents or real licenses are issued.
VAT Validator
Check VAT formats locally, with an optional EU VIES request for registration status.
Test your device in the browser
New Tools
browse all- Numerology AnalyzerLife Path, Destiny, Soul Urge and Personality numbers from a birth name and date.Daily & Lifestyle
- Human Design BodyGraphNine-center Human Design bodygraph from birth time and place.Daily & Lifestyle
- Biorhythm CalculatorPhysical, emotional and intellectual sine waves for the next 30 days.Health & Lifestyle
- Golden & Blue HourTwilight, golden hour and blue hour windows for any date and place.Creator & Business Tools
- Moon Gardening CalendarPlant by waxing or waning moon and zodiac part — leaf, root, flower, fruit.Daily & Lifestyle
- Intermittent Fasting PlannerAlign 16:8 and other protocols with local sunrise on a 24-hour clock.Health & Lifestyle
- Life in WeeksA memento-mori grid of weeks with optional life milestones.Daily & Lifestyle
- BMR & TDEE CalculatorMifflin-St Jeor or Harris-Benedict calories plus cut, maintain and bulk macros.Health & Lifestyle
- Ephemeris CalculatorCompute tropical longitudes, RA and declination for the Sun, Moon and planets offline.Data Processing
- Natal ChartDraw a birth chart wheel with Placidus, Whole Sign or Equal houses.Visual Tools
Browse by category
Every tool runs in your browser — pick a category to dive in, or press ⌘K to search.
Color Tools
Color utilities and generators
Color Blindness Simulator · Color Contrast Checker · Color Converter
Design Tools
Theme builders and design asset generators
Aspect Ratio Calculator · Border Radius Generator · Box Shadow Generator
Data Processing
Format, convert and process data
Base64 Toolbox · C# to VB.NET Converter · CSV Data Viewer
Text & Analysis
Text processing and analysis tools
Anagram Solver & Palindrome · Binary Text Translator · Case Converter & Text Formatter
Generators
Generate IDs, references and more
ABA Routing Number Generator · Address Generator · ASCII Text Art Generator
Security Tools
Security analysis and authentication tools
AES Encryption · Basic Auth Generator · Bcrypt Generator & Verifier
Network & API Tools
HTTP clients and network utilities
API Mock Server · Bandwidth Calculator · Broken Link Checker
Development Utilities
Essential utilities for developers
.env Secret Safety Linter · .htaccess Generator · 2D Fluid Dynamics & Particle Physics Sandbox
Visual Tools
Preview and convert visual content
APCA Contrast Calculator · Barcode Generator · Base64 Image Encoder
Creator & Business Tools
Privacy-first helpers for creator payouts and business workflows
Code Snippet to Image · Creator Tax Form Guide · Freelance Invoice Generator
Media & Audio
Record, convert and edit audio and video in your browser
Audio Trimmer & Cutter · Canvas WebM / Animated GIF Exporter · Screen & WebCam Recorder
Sound Tools
Synthesizers, sound effects and sound generation in your browser
Ambient Noise Generator · Audio BPM Tap & Tempo Detector · Audio dBFS, dBu, dBV & Voltage Converter
Financial Tools
Loan, interest, tax and currency calculators
Compound Interest Calculator · Currency Converter · Discount & VAT Calculator
Productivity Tools
Focus timers, health calculators and speed tests
BMI & TDEE Calculator · Habit & Streak Tracker · Pomodoro Focus Timer
Device & Sensors
Device orientation, sound, camera and location utilities
Digital Bubble Level · Digital Compass · Flashlight & Signal Beacon
Education & Science
Learning, exams, grades and scientific references
3D Affine Transform Visualizer · Exam & Section Timer · Flashcards & Spaced Repetition
Daily & Lifestyle
Kitchen, travel, clothing and everyday planning
Clothing & Shoe Size Chart · Fuel Cost & Trip Calculator · Human Design BodyGraph
Health & Lifestyle
Informational sleep and pregnancy planning tools
Biorhythm Calculator · BMR & TDEE Calculator · Intermittent Fasting Planner
Randomness & Games
Fair random choices, dice and raffles
3D Dice Roller & Coin Flip · Decision Wheel & Picker · Random Number & Raffle Picker
Games
Single-player browser games — play instantly, progress saved in your browser
2048 · Memory Match · Minesweeper
Time & Productivity
Stopwatches, countdowns and pacing tools
Fullscreen Countdown Timer · Precision Stopwatch
AI Tools
Assemble context, manage prompts and prep RAG data for LLM workflows
Agent Tool Flowchart Builder · AI Agent Memory & Buffer Simulator · AI API Client SDK Generator
Frequently asked questions
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