Random Number Generator
Generate random numbers in any range. Single numbers, lists, or unique sets. Free browser-based tool — no sign-up.
How Random Number Generator Works
Set minimum and maximum values, choose how many numbers to generate, and optionally require unique numbers only. Generation uses the browser's crypto.getRandomValues() API — not Math.random().
Use Cases
Generate random number generator
Create random random number generator instantly with customizable options for your number tools needs.
Bulk Generation
Generate multiple random number generator at once for testing, batch processing, or bulk operations.
Copy & Use
Copy generated results with one click and use them directly in your applications or workflows.
Customize Options
Fine-tune random number generator generation with various settings and filters for specific requirements.
Frequently Asked Questions
Is this truly random?
Yes — this tool uses crypto.getRandomValues(), the browser's cryptographic random number generator. This is different from Math.random() which is pseudorandom (deterministic given the same seed). crypto.getRandomValues() is suitable for security-sensitive applications.
What is the maximum range I can use?
The tool supports any integer range up to JavaScript's safe integer limit (±9,007,199,254,740,991). Practically, generating unique numbers from a very large range works well; generating 1,000 unique numbers from a range of 1–1,000 works but gets slower as it fills up.
Can I generate decimal numbers?
The default mode generates integers. Enable decimal mode to generate floating-point numbers with a specified number of decimal places.
Is my data stored?
No.
Can I use this on mobile?
Yes.
About This Tool
Built by the Calcyo team and last updated June 2026. All calculations follow industry-standard methodology. No data leaves your browser — calculations run entirely client-side using JavaScript. If you spot an error in the formula or benchmark data, email us at support@calcyo.xyz.