Randomnumbers.co : The Ultimate Random Numbers Generator
Press a button. Get a fair random number. Nothing is saved, sent or tracked.
- Free forever
- No sign-in
- No cookies or tracking
- Works offline
Quick answers
What is a random number generator?
The six things everyone wonders first
-
Is it really random?
Random enough to be used for encryption. We use your browser’s secure engine, not Math.random().
-
Can I get the same number twice?
Yes, like real dice. Switch on “No repeats” if you want every number different.
-
Does anyone see my numbers?
No. They are made on your device and are never sent anywhere. Turn off Wi-Fi and try.
-
Do I need to sign in?
Never. No account, no password, no email. Just press the button.
-
Is it free and fast?
Free, with no limits. Results appear instantly because nothing waits on a server.
-
Does it work on my phone?
Yes. It is built mobile-first, and works offline once the page has loaded.
In 3 steps
Three taps to a random number
Set your range
Type a lowest and a highest number, or tap a preset like 1–100.
Press Generate
Ask for one number or thousands, with or without repeats.
Copy or go again
Copy the result in one tap. Nothing is kept once you leave.
Types of random number generators
Three kinds of “random”, explained so a 6-year-old gets it
Not all random numbers are made the same way. Here is the whole story in three cards, and which one we use.
-
Pseudo-random (PRNG)
The recipe
Like you’re six Like a super-mixed-up recipe for scrambling numbers. Start from the same starting number, called the seed, and you get exactly the same scramble every time.
- How it works
- A math formula turns a seed into a long stream of numbers that look random.
- You have met it in
- Video-game worlds (a Minecraft world seed), spreadsheet RAND(), simulations.
- Great for
- Fast, and repeatable: great for games, teaching and testing.
- Not for
- Secrets. If someone learns the seed, they know every number.
- What we use
Cryptographically secure (CSPRNG)
The recipe + surprises
Like you’re six The same kind of recipe, but your device keeps stirring in tiny surprises from the real world: the exact timing of your taps, and electrical fizz inside the chip. Even a clever spy cannot guess the next number.
- How it works
- A strong formula that is constantly re-seeded with unpredictable noise from your hardware.
- You have met it in
- The padlock in your browser, password managers, secure messaging.
- Great for
- Unpredictable enough to protect banks. Instant, and works offline.
- Not for
- Almost nothing: it is the right choice for nearly every job.
-
True random (TRNG)
Nature’s dice
Like you’re six No recipe at all. The numbers come from something truly unpredictable in nature, like radio static in the sky, or even a wall of lava lamps that a camera watches.
- How it works
- Special hardware measures a physical process, like atmospheric noise or radioactive decay.
- You have met it in
- RANDOM.ORG (atmospheric noise), lava-lamp walls, quantum random services.
- Great for
- Truly unpredictable, even in theory. Useful for research and special draws.
- Not for
- Speed and privacy: it needs special hardware, usually on someone else’s server.
Why not true random (TRNG) here?
True random needs special hardware or someone else’s server, which means your request leaves your device and can be seen, logged or slowed down. Your device’s secure engine already mixes in real-world noise, so you get unpredictable numbers instantly and privately. If you specifically need physical randomness, for research or a draw that must be certified, use a dedicated service like RANDOM.ORG.
Fairness lab
Don’t trust us. Test us.
Roll 10,000 numbers right now, in your browser, and see whether every number really gets its fair share. The dashed line is what perfect fairness looks like.
Press the button and watch 10,000 rolls land on the chart.
How to read this
Lumpy is normal. Real randomness is never perfectly even: some numbers will come up a bit more than others, and the next run will shuffle who is on top.
The fairness score comes from a chi-square test. A fair generator scores above 0.05 about 95 times in 100, and below 0.001 only about once in 1,000 runs. Scores that are suspiciously close to 1 every time would be a red flag too, since that means “too even”.
Our automated tests run similar checks on every change, on every tool on this site.
What people use it for
Random numbers are everywhere
-
Board & tabletop games
Roll d20s, 2d6 and more.
-
Classrooms
Call on students fairly, make groups.
-
Giveaways & raffles
Draw winners with no repeats.
-
Settling debates
Heads or tails, yes or no.
Science & statistics
Samples and simulations, with seeds for repeatable runs.
-
Developers & testers
Test data, tokens, IDs.
-
Lottery quick-picks
Tickets with the real odds shown.
-
Bingo & party games
Draw 1–75 with no repeats.
Privacy, explained simply
Privacy, explained like you’re 6
Here is everything we did to keep your numbers yours, with grown-up details underneath each one. Short version: we built a website that cannot spy on you, because there is nothing in it to spy with.
Your numbers are born on your device
Like you’re sixIt is like rolling a die at your own table. Nobody across the room can see it.
For grown-ups: The generator is code that runs in your browser. Pressing Generate makes no network request, and the number never travels anywhere.
No sign in
Like you’re sixLike a slide at the playground. You do not need a ticket or to tell anyone your name. You just slide.
For grown-ups: There are no accounts, no email addresses and no profiles. There is nothing to sign in to.
No password
Like you’re sixYou cannot lose the key to a door that does not exist. Nothing to forget, nothing to steal.
For grown-ups: No passwords means no password database to leak, no resets and no phishing target.
No database
Like you’re sixWe do not have a notebook where we write down what you did. We are like a water fountain: it does not remember who had a drink.
For grown-ups: The site is just static pages. There is no server code and no database, so there is nowhere to keep your results even if we wanted to.
No cookies, no trackers
Like you’re sixCookies are like stickers some websites secretly stick on your back to follow you around. We have no stickers.
For grown-ups: No cookies, no local storage, no fingerprinting and no third-party scripts. At launch there is not even a visit counter.
We keep our own fonts and pictures
Like you’re sixSome websites borrow their pretty letters from a faraway shop that notes down who came to visit. We keep our own letters in our own backpack.
For grown-ups: Fonts, icons and images are served from our own domain. No Google Fonts, no CDNs, so no third party learns that you visited.
A guard at the door
Like you’re sixYour browser acts like a guard that will not let our page talk to strangers, even if someone tried to trick it.
For grown-ups: A strict Content-Security-Policy (connect-src ‘self’, no third-party scripts) makes your browser refuse any request to another server. It also blocks framing, and we send a no-cross-site referrer policy.
Works with the Wi-Fi off
Like you’re sixIf it still works when the internet is switched off, then nothing can be going out. Try it!
For grown-ups: After your first visit, a small service worker keeps the site in your browser so every tool keeps working offline. You can also install it like an app.
Fair, not rigged
Like you’re sixWe did extra math so no number is secretly favoured, like making sure every ping-pong ball weighs exactly the same.
For grown-ups: Rejection sampling removes modulo bias, and our automated tests check uniformity with chi-square statistics. Our code is not even allowed to use Math.random(): the linter fails the build if anyone tries.
Don’t take our word for it
Verify it yourself in 30 seconds
- 1 Turn off the internet
Load the page, switch on airplane mode, then press Generate. It still works.
- 2 Watch the network
Open your browser’s developer tools, choose the Network tab, press Generate. Nothing is sent.
- 3 Run the fairness lab
Roll 10,000 numbers right here and see every number come up about equally often.
Nothing you generate is sent anywhere. How we know
How we make sure it stays true
-
Your browser enforces it
A strict security policy stops our page from contacting any other website. Even a bug could not leak your numbers.
-
Our code checker enforces it
Our build fails if anyone adds cookies, browser storage, network calls, or Math.random() to the site.
-
Automated tests enforce it
Dozens of tests check that every number, die, coin and pick is fair, plus the exact lottery odds.
What we cannot hide (and will not pretend)
- Like every website, when you open a page our hosting provider (Cloudflare) sees a normal visit: your IP address and the page you asked for, the same way a shop owner sees someone walk in. It cannot see the numbers you generate, because those are made on your device after the page has loaded.
- If we ever add visitor counting such as Google Analytics, we will ask you first, explain it here, and it will never see your numbers, lists or settings.
- Closing or refreshing the tab forgets everything. Copy results you want to keep.
How we compare
The classics are great. We built it for how people use it today.
RANDOM.ORG and calculator.net have earned their rankings. Here is an honest, side-by-side look, checked in a real browser on October 18, 2026, including the rows where they win. A dash means we did not check it.
| What matters | Randomnumbers.cothis site | RANDOM.ORGrandom.org | calculator.netrandom number page |
|---|---|---|---|
| Where the randomness comes from Matters for security and for special draws. | Your device’s secure engine (CSPRNG), seeded from hardware noise | Atmospheric noise: true random (TRNG) | Pseudo-random; its page says not for cryptography |
| Numbers are made on your device If they never leave, nobody can see or log them. | Yes. Nothing is sent | No. A server makes them; your range goes in the page address | No. A server makes them; your range goes in the page address |
| Works offline after the first visit Planes, classrooms and flaky Wi-Fi. | Yes, even after reloading the page | No. Every number needs their server | No. Every number needs their server |
| Cookies set before you click anything A fresh browser, one page view. | None | 2 (a session cookie and a Cloudflare one); has a cookie notice | 2 (a session cookie and a 30-day one) |
| Ads on the page Ads slow pages down and move things around. | None | None (“We do not carry ads”) | Yes. A Google ad slot is built into the page |
| Works with JavaScript turned off Reader modes and strict privacy browsers. | No. The generator runs in your browser, so it needs JavaScript | Yes | Yes |
| Free, with no sign-in The basics. | Yes | Yes | Yes |
| Usage limits Can you run out? | None | A free quota of random bits per IP address (1,000,000 when we looked) | Not compared |
| Very large numbers Cryptography and maths work. | Up to 1,000 digits | Integers limited to ±1,000,000,000 | Thousands of digits (3,000 confirmed); its number box stops near 300 in Chrome |
| How many kinds of generator One place for everything random. | 7 tools in one design | 24 in its menu: games, numbers, lists and more | A number page and a dice roller inside a general calculator site |
yes no partly — not compared
Fair is fair
If you need true, physical randomness (atmospheric noise), a very wide menu of generators, or numbers beyond 1,000 digits, those sites are the right tools. If you want something instant, private, offline-ready and friendly on a phone, that is what we are for.
Only here
-
A fairness lab
Roll 10,000 numbers and see the proof on a chart.
-
A live privacy meter
Counts the requests your browser makes while you generate.
-
Explained for a 6-year-old
PRNG, CSPRNG and TRNG, with everyday examples.
-
Seeded mode
Share a seed and get the same numbers on every device.
-
Offline-ready
Install it like an app and keep rolling without a connection.
-
No cookies, no banner, no sign-in
Nothing between you and the button.
Sources and how we checked
On October 18, 2026 we opened each site in a clean browser with nothing saved, looked at what it stores, what it loads, what happens when you press the button, with the network switched off and with JavaScript turned off, and read what each site says about itself. Sites change, so please check the source if something matters to you.
- RANDOM.ORG home: atmospheric noise, “We do not carry ads”, cookie notice
- RANDOM.ORG integer generator: the ±1,000,000,000 limit
- RANDOM.ORG quota page: the free allowance of random bits
- calculator.net random number generator: pseudo-random, “should not be used for cryptographic purposes”, “up to a few thousand digits”
All the tools
One home for every kind of random
Seven free tools, one design, one promise. Each has its own page, so you can bookmark the one you use most.
-
Random Number Generator
Any range, decimals, no repeats, up to 1,000 digits.
Open -
Online Dice Roller
d4 to d100, many dice, modifiers, advantage.
Open -
Coin Flip: Heads or Tails?
Heads or tails, or flip up to 10,000 coins.
Open -
Random Name Picker (with Spinning Wheel)
Spin a wheel, pick winners, split into teams.
Open -
Lottery Number Generator
Quick-pick tickets for Powerball, Mega Millions and more.
Open -
Random String Generator
Secure random tokens, hex keys and IDs with entropy shown.
Open -
UUID Generator (v4 & v7)
Bulk UUID v4 and time-sortable v7, entirely in your browser.
Open
Popular searches
FAQ
Every question people ask about random numbers
What is a random number generator?
A random number generator (RNG) is a tool that produces numbers with no pattern, where every number in the range is equally likely and the next number cannot be predicted from the last. People use them for games, raffles, classroom activities, research, software testing and security.
How do I generate a random number between two numbers?
Type your lowest number in “Min” and your highest in “Max” (for example 1 and 100), then press Generate. Both ends are included, so a range of 1 to 100 can return 1 or 100. Use “How many” to get a whole list at once.
Are the numbers truly random?
They come from your browser’s cryptographically secure random generator (crypto.getRandomValues), which is continuously seeded with unpredictable hardware noise. This is the same source used to create encryption keys, and for every practical purpose it is indistinguishable from true randomness. If you specifically need physical randomness such as atmospheric noise, a service like RANDOM.ORG provides it.
What is the difference between pseudo-random and true random numbers?
Pseudo-random numbers come from a formula and a starting value called a seed, so the same seed gives the same numbers. True random numbers come from physical processes such as atmospheric noise or radioactive decay and cannot be reproduced. A cryptographically secure generator, which is what this site uses, sits in between: a strong formula that is constantly re-seeded with real-world noise.
Can I get the same number twice?
Yes, unless you switch on “No repeats”. Random does not mean “different each time”: with a 1 to 10 range, there is a 10% chance that two picks in a row match. Real randomness repeats more often than people expect, which is why “No repeats” exists.
How do I generate random numbers without repeats?
Tick “No repeats” and choose how many numbers you need. For example, set 1 to 49 and ask for 6 to get six different numbers. The tool returns an error if you ask for more different numbers than the range contains.
Is the generator fair and unbiased? How can I check?
Yes. We use rejection sampling to remove “modulo bias”, so every number has exactly the same chance. You can test it yourself with the Fairness Lab on this page: it generates 10,000 numbers and shows how evenly they landed, with a chi-square statistic. Small wobbles are normal, since real randomness is lumpy.
Is it free? Do I need to sign up?
It is free, with no limits, and there is nothing to sign up for. No account, no password and no email address, ever.
Does Randomnumbers.co see, save or sell my numbers?
No. Numbers are generated inside your browser and never sent to us, because there is no server code or database to receive them. Your browser also enforces this with a strict Content-Security-Policy. Like any website, our host sees that a page was visited, but never what you generated.
Does it work offline?
Yes. After your first visit the site keeps itself in your browser, so all tools work without an internet connection. You can also add it to your home screen or install it like an app.
Can I generate decimals, negative numbers or huge numbers?
Yes to all three. Choose “Decimals” and a number of decimal places (up to 20), use negative limits such as -50 to 50, or enter limits with up to 1,000 digits. You can ask for up to 10,000 numbers at once.
What is a seed, and can I repeat a result?
A seed is the starting value of a pseudo-random generator. In “Seeded” mode, the same seed and settings give exactly the same numbers on every device, which is handy for teachers, games and reproducible experiments. Seeded results are repeatable by design, so use the default Secure mode for anything that must stay unpredictable.
Can I use it for raffles, giveaways and classroom picks?
Yes. Use the Name Picker to draw several different winners or split people into teams, or the number generator with “No repeats” for ticket numbers. For official or high-stakes draws, check your local rules and consider recording your screen as evidence.
Is it safe to use for passwords or security keys?
The numbers come from a cryptographically secure source, so the randomness is strong. For passwords and secrets, though, a password manager is the best tool since it also stores and fills them for you. For tokens and IDs, use our Random String Generator, which shows the entropy in bits.
Why do people think 7 and 37 are the most random numbers?
Humans are poor random number generators. We avoid the ends of a range and favour numbers that feel unremarkable. 7 is the most popular “random” pick between 1 and 10, and in a Veritasium survey of over 200,000 people asked for a number from 1 to 100, 37 came out on top. A real generator picks every number equally often.
How is this different from the random number generator in Google search?
A search-box widget is handy for a single number between two limits. This site adds lists of numbers, no repeats, decimals, negative and huge ranges, a repeatable seed mode, dice, coins, a name picker, lottery and UUID tools, a fairness lab, and it keeps working offline.
Ready? Press the button.
Free, fast and private. No sign-in, ever.