Simple Random Number Generator
Generate random integers or decimals within any range. Uses the most reliable source of randomness available in your browser. Works offline.
Vocabulary for translation plugins
Minimum
Maximum
How many numbers
Mode
Integers
Floats
Precision
Generate
Copy output
Results
Ready.
Generated numbers.
Error
Nothing to copy.
Copied to clipboard.
Copy failed.
Random source: Crypto (window.crypto)
Random source: Math.random fallback
Self-tests
Test error:
Test
PASS
FAIL
Tests passed
Tests failed
Verdict
Tests passed; app seems to be behaving as expected.
App has failing tests and should not be trusted.
Golden integers from fixed sequence
Integer bounds [5, 7]
Float inclusive precision
Float upper-bound clamping
Validation rejects invalid params
Crypto source detection
Negative range integers
min equals max
Integer lower bound (u=0)
Validation accepts valid params
Float with zero decimals
Single number generation
Offline cache not available in this browser.
Description
This tool produces random numbers within any range you define. It can generate either whole numbers or decimal values, and it uses the most reliable source of randomness available in your browser. When possible, it relies on a cryptographically secure generator (CSPRNG); if not supported, it automatically switches to the standard mathematical generator.
This generator is suitable for everyday use (lottery picks, quick sampling, dice alternatives) as well as for more technical needs where the quality of randomness matters.
Instructions
- Set the limits – choose the minimum and maximum values.
- Select how many numbers to generate – you can create a single value or a sequence.
- Choose the mode – Integers: whole numbers only. Floats: decimal values.
- Define precision (floats only) – number of decimal places (up to 12).
- Press Generate – results appear in the box below.
- Copy output: saves the generated numbers to your clipboard for reuse.
- Randomness source indicator: shows whether numbers come from the secure Crypto generator or from the fallback (Math.random).
- Crypto generator (CSPRNG): It is the generator provided by the browser (window.crypto). It gathers entropy from the operating system and produces numbers designed to be unpredictable and suitable for security-sensitive uses such as encryption keys. When available, this is the default.
- Math.random: It is the standard JavaScript random number generation function. It is fast and sufficient for casual use, but its output is deterministic once the algorithm is known, and it is not considered secure for cryptographic or high-stakes applications.