Number Primality Test
Instantly check whether a number is prime using a fast, deterministic, and privacy-first primality test that runs entirely in your browser. No data leaves your device-ever.
Primality Test Tool
About This Tool
This number primality test determines whether a given integer is divisible only by 1 and itself. It uses an optimized deterministic Miller-Rabin algorithm implemented with JavaScript BigInt for high accuracy and performance, even for very large numbers.
Key Benefits of Using This Tool
- Runs 100% locally in your browser
- No tracking, cookies, or data collection
- Accurate for large integers using BigInt arithmetic
- Instant results with minimal CPU usage
- Accessible on desktop and mobile devices
Features
- Deterministic primality testing
- Support for very large numbers
- Responsive, mobile-friendly interface
- Light-mode only for maximum readability
- SEO-optimized, globally accessible page
Use Cases
- Students learning number theory
- Developers validating prime inputs
- Cryptography experimentation and learning
- Competitive programming practice
- Quick verification of mathematical problems
Fun Fact
The largest known prime numbers each contain millions of digits and are often discovered using distributed computing projects that rely on advanced primality testing algorithms.
Historical Context
Prime numbers have fascinated mathematicians for over two thousand years. Euclid proved their infinitude around 300 BCE, and modern primality testing algorithms now play a foundational role in digital security, encryption, and computational mathematics.