Developer Tools for Random Data Generation // v2.13.1
root@generate-random:~/numbers$ _

Random Number Generator

Generate random numbers with customizable ranges and options

Our random number generator helps you generate random numbers with customizable ranges. Generate-Random.org provides a free number generator that creates integers, decimals, primes, and percentages. This CSPRNG number generator uses cryptographically secure random number generation for maximum security. Generate up to 1,000 numbers with options for unique values, sorting, and bulk export. Perfect for lottery number generation, statistical sampling, and dice simulation. All numbers generated with cryptographic-quality randomness. No signup required, completely free.

What is a Random Number Generator?

A Random Number Generator (RNG) is a computational or physical device designed to generate sequences of numbers that lack any pattern. Our generator uses cryptographically secure algorithms to ensure true randomness for all applications.

Random numbers are essential in various fields including statistics, cryptography, gaming, simulations, and scientific research where unpredictable values are required. For text-based randomization, try our string generator.

Number Generator Configuration Options

Range Configuration (Min/Max Values)

Define the boundaries for random number generation by setting minimum and maximum values. The generator ensures uniform distribution across the entire range, meaning every number within the range has equal probability of being selected. Range Features: Minimum value (-1,000,000 to 1,000,000), maximum value (must be greater than minimum), inclusive range (both min and max values can be generated), uniform distribution with cryptographically secure randomness ensures no bias.

Number Type Selection

Choose between integer (whole numbers), decimal (floating-point), prime, or percentage based on your application needs. Integers: Discrete values without decimal points like -1000, 0, 42, 999—perfect for counting, indexing, IDs, lottery numbers. Decimals: Continuous values with decimal precision (1-10 digits) ideal for scientific calculations and probabilities. Prime Numbers: Generated using Sieve of Eratosthenes algorithm for cryptography and mathematics. Percentages: Values between 0-100% for probabilities, grades, and A/B testing.

Quantity (1-1000 Numbers)

Generate multiple random numbers simultaneously for batch operations, statistical analysis, or bulk data needs. Each number is independently generated with cryptographically secure randomness, ensuring no patterns or correlations between numbers. Generate 1-1000 numbers in a single operation with efficient batch processing.

Unique Numbers (No Duplicates)

Ensure all generated numbers are unique with no duplicates. This option implements sampling without replacement, where each number can only appear once in the result set. Essential for lottery systems, random selection, and scenarios requiring distinct values. Note: quantity cannot exceed range size when unique is enabled.

Sorting Configuration

Organize generated numbers in ascending, descending, or random order. Sorting does not affect the randomness of generation—numbers are first randomly generated, then optionally sorted for presentation. This is purely a display preference and does not compromise cryptographic security.

How to Generate Random Numbers

[STEP 1] Set Range

Configure minimum and maximum values to define your number range. Ensure min is less than max.

[STEP 1] Choose Type

Select between integers, decimals, primes, or percentages based on your needs.

[STEP 1] Configure Options

Enable unique numbers, sorting, or other options as required for your use case.

[STEP 1] Generate & Export

Click generate and export results in TXT, CSV, or JSON format with included statistics.

Common Use Cases for Random Numbers

  • _ Statistical Sampling: Generate random samples for data analysis and research studies
  • _ Random Selection: Conduct fair contests, giveaways, and prize drawings with unbiased selection
  • _ Gaming & Simulations: Create dice rolls, lottery numbers, and game mechanics with true randomness
  • _ Scientific Experiments: Run Monte Carlo simulations and probability experiments
  • _ Cryptographic Applications: Generate keys and security tokens with cryptographic quality randomness
  • _ Software Testing: Create random test data for development and QA automation

Technical Details: Random Number Generation Algorithm

Our number generator employs cryptographically secure random number generation (CSPRNG) with uniform distribution across specified ranges. The system validates input boundaries, applies precision controls for decimal numbers, and ensures unbiased random selection using rejection sampling when necessary. All numbers are generated with statistical randomness that passes rigorous entropy tests.

// Random integer generation with uniform distribution
N = min + ⌊R × (max - min + 1)⌋ where R ∈ [0,1) uniformly

// Decimal generation with precision control
x = min + R × (max - min), rounded to d decimal places

// Prime number generation
Algorithm: Sieve of Eratosthenes + Random Selection
1. Generate all primes in range using Sieve
2. Randomly select from prime list with CSPRNG
3. Ensure uniform distribution across prime candidates

// Unique number generation (sampling without replacement)
Algorithm: Fisher-Yates Shuffle Variant
1. Create pool of all valid numbers in range
2. For each number needed:
   - Generate random index with CSPRNG
   - Select and remove number from pool
3. Return unique set

Security: CSPRNG meets NIST SP 800-90A standards

API Access for Developers

GET https://generate-random.org/api/v1/generate/numbers
VIEW FULL API DOCUMENTATION

Frequently Asked Questions

What is true randomness?
True randomness means each number is generated independently with equal probability within the specified range. Our generator uses cryptographically secure pseudo-random number generators (CSPRNG) that pass statistical randomness tests and meet NIST SP 800-90A standards for security-critical applications.
What's the difference between the number types?
Integer generates whole numbers (1, 2, 3). Decimal generates numbers with decimal points (1.23, 4.56) with configurable precision. Prime generates only prime numbers (2, 3, 5, 7, 11...) using the Sieve of Eratosthenes algorithm. Percentage generates values between 0-100% for probability and grade calculations.
Can I generate unique numbers without duplicates?
Yes, enable the 'unique' option to ensure all generated numbers are different. This uses sampling without replacement, perfect for lottery numbers, raffle draws, and random sampling. Note: the count cannot exceed the range when unique is enabled (e.g., 1-10 range = max 10 unique numbers).
What's the maximum range I can use?
You can generate numbers from -1,000,000 to 1,000,000, which covers virtually all common use cases. The API supports even larger ranges for programmatic access. For lottery-specific number generation, see our dedicated lottery number generator.
How are decimal numbers generated?
Decimal numbers are generated using cryptographically secure random bytes converted to floating-point values with your specified decimal precision (1-10 places). This ensures uniform distribution across the decimal range with no bias toward any particular values.