DIY Cost Tools
Random Number Generator
MATH TOOL
Generate one or more random integers within an inclusive range, with or without duplicate values.
How it works
Choose inclusive integer bounds and a result count. When available, the generator uses the browser’s cryptographic random source and rejection sampling to avoid modulo bias.
Formula
For each draw, an unbiased random integer offset from 0 through range size − 1 is added to the minimum.
Worked example
For a range of 1 through 100 and a count of five, the tool returns five integers. Each click produces a new result.
Important limits
- This tool generates integers only.
- Results should not be treated as proof of fair gaming, regulated drawing compliance, or scientific sampling design.
- Without duplicates, the requested count cannot exceed the number of integers in the range.
Frequently asked questions
Are the endpoints included?
Yes. Both the minimum and maximum can be selected.
Can I reproduce the same sequence?
No. The tool does not expose or store a seed.
Sources and review notes
The tool prefers the browser Web Crypto random-value generator when available; its fallback is intended only for ordinary nonsecurity use. Last reviewed September 29, 2026.