Unit Converter 2026: Free All-in-One Online Conversion Tool
Convert length, weight, temperature, area, volume, speed, and time with millisecond precision. The most advanced, free online unit converter for global users in 2026. No ads, no sign-up, 100% privacy-focused.
Start Converting NowAll-in-One Unit Converter
Common Conversions
Conversion History
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Why Choose Our Unit Converter?
Real-time Precision
Get instant, accurate results with up to 16 decimal places. Our algorithm uses official conversion standards from NIST and BIPM for scientific-grade accuracy.
Global Standards
Supports SI, Imperial, US Customary, and scientific units. Perfect for international travel, engineering projects, and academic research across different measurement systems.
100% Privacy Focused
All conversions happen locally in your browser. We never store, track, or transmit your data. Your privacy is guaranteed with our zero-data-collection policy.
Mobile Optimized
Fully responsive design with touch-friendly interface. Works perfectly on smartphones, tablets, and desktops. Progressive Web App (PWA) ready for offline use.
Frequently Asked Questions
Absolutely free with no hidden costs! Our unit converter is 100% free, with no subscription fees, no premium paywalls, and most importantly—no advertisements. We believe in providing accessible tools for everyone, funded by our mission to improve digital utility access.
Our conversions use industry-standard conversion factors from authoritative sources including:
- National Institute of Standards and Technology (NIST)
- International Bureau of Weights and Measures (BIPM)
- International System of Units (SI) 2026 standards
The tool handles up to 16 decimal places and scientific notation, making it suitable for engineering calculations, scientific research, and academic work.
No data storage or tracking. All conversions are performed locally in your browser using JavaScript. History is stored only in your browser's local storage and never transmitted to our servers. We adhere to a strict zero-data-collection policy. Read our full Privacy Policy for complete details.
Our mobile experience is built with these advanced features:
- Mobile-first responsive design with perfect Core Web Vitals scores
- Touch-friendly interface with large buttons and swipe gestures
- Offline functionality as a Progressive Web App (PWA)
- Instant results without page reloads
- Dark/Light mode with automatic system detection
Yes! Our converter includes advanced features:
- Batch conversion: Convert one value to all relevant units simultaneously
- Conversion history: Access your last 50 conversions with one click
- Quick presets: Save frequently used conversions for instant access
- Shareable results: Generate unique URLs to share specific conversions
We support 7 comprehensive categories with dozens of units each:
- Length: Meters, Kilometers, Miles, Feet, Inches, Yards, etc.
- Weight: Kilograms, Grams, Pounds (lbs), Ounces, Stones, Tons, etc.
- Temperature: Celsius, Fahrenheit, Kelvin
- Area: Square Meters, Acres, Square Feet, Hectares, etc.
- Volume: Liters, Milliliters, Gallons, Cubic Meters, etc.
- Speed: km/h, mph, m/s, knots, etc.
- Time: Seconds, Minutes, Hours, Days, Weeks, Months, Years
Temperature conversion uses formula-based calculations rather than multiplication factors:
- Celsius to Fahrenheit: (°C × 9/5) + 32
- Fahrenheit to Celsius: (°F - 32) × 5/9
- Celsius to Kelvin: °C + 273.15
- Kelvin to Celsius: K - 273.15
This ensures absolute accuracy for temperature conversions where linear scaling doesn't apply.
Yes, we're committed to full accessibility:
- WCAG 2.1 AA compliant design
- Full keyboard navigation support
- Screen reader compatibility
- ARIA labels and roles throughout
- High contrast modes
- Focus indicators for all interactive elements