Random Number Generator

Sometimes you just need a number: a raffle ticket, a dice roll, a lottery line or a random row to audit. FreePDF’s random number generator gives you as many integers as you need in any range, with an option to forbid repeats, using secure randomness so the results cannot be predicted or skewed. It works offline once loaded and keeps a timestamped copy of each draw you download.

Common uses

• Draw the winning raffle ticket from those sold.
• Roll virtual dice for board games and role-playing games.
• Generate lottery-style lines of unique numbers.
• Pick random sample rows from a spreadsheet or database for quality checks.
• Create random seat, group or question numbers for a classroom.

Tips for best results

• For dice, use 1–6 (or 1–20 for a d20) and allow repeats.
• For lottery lines, tick “Unique” and sort the result.
• When sampling data, set the maximum to your row count and pick without repeats.
• You can ask for up to the full range when “Unique” is on – that is a complete shuffle.
• Download the result to keep a record of what was drawn and when.

Uniform randomness explained

A fair generator gives every number in the range the same probability. That sounds simple, but turning random bits into a range such as 1–37 can introduce a small bias if done carelessly, because 37 does not divide evenly into a power of two. The generator uses rejection sampling: it discards the few raw values that would cause bias and draws again. The result is mathematically uniform, which matters when prizes or fairness are at stake.

With or without repeats

Drawing “with repeats” is like rolling a die: each roll is independent and the same value can come up again. Drawing “without repeats” is like pulling balls from a bag: once a number is chosen, it cannot be chosen again, so you can never draw more numbers than the range contains. Lotteries, raffles and random sampling usually need unique numbers; dice and simulations usually allow repeats.

Random sampling for audits and research

Quality teams and researchers often check a random subset instead of every record. Number your rows, set the range to match, pick the sample size without repeats and sort the result to make lookup easy. Because the numbers are unpredictable, nobody can steer which records are checked. For formal statistical work, note the date and method in your report – the downloaded file contains both.