PALLAS / BUILDER
Random Number Generator
Generate inclusive integer or fixed-decimal samples, unique sets or shuffled sequences locally with the Web Crypto API. The tool describes its source as a cryptographically strong pseudorandom generator, not physical true randomness.
INPUT
Enter values
Method & formula
The engine draws unsigned 64-bit values from Crypto.getRandomValues and maps them into the requested discrete range with rejection sampling, which avoids modulo bias. Fixed-decimal mode converts the chosen decimal grid into an integer sampling space; shuffle mode uses the same unbiased sampler in a Fisher–Yates shuffle.
- Unbiased range sampling: reject draws at or above the largest multiple of range size below 2^64
- Unique mode: reject the request before generation when quantity exceeds the available discrete values
Example
For integers from 1 to 10 with quantity 5 and unique mode enabled, the tool returns five distinct values. Asking for 11 distinct values is rejected before any generation occurs.
Sources & standards
FAQ
Is this true random?
It uses the browser Web Crypto cryptographically strong pseudorandom generator. It does not claim atmospheric, quantum or other physical entropy of the kind used by specialised true-random services.
Can unique mode silently repeat values?
No. The engine tracks generated values and rejects impossible requests where the requested quantity exceeds the discrete range.
How are decimal endpoints handled?
Decimal mode samples an inclusive fixed decimal grid. If an endpoint has more decimal places than the selected precision, the request is rejected rather than rounded silently.