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Random Number Generator
Pick numbers in any range — one or thousands, whole or decimal, with or without repeats. Drawn from your browser's cryptographic source with unbiased sampling.
Result
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🎲 Genuinely unbiased. Most quick implementations do
Math.random() * range, which is both predictable and slightly skewed. This page uses crypto.getRandomValues() with rejection sampling, so every number in your range is exactly as likely as every other — which matters for draws, sampling and anything anyone might contest.
HOW IT WORKS
Why "Random Enough" Usually Isn't
Two things quietly go wrong in most random number code. The first is the source: Math.random() is a fast statistical generator whose future output can be predicted from past values, which is fine for animations and fatal for anything anyone could gain from guessing. The second is subtler — taking a random value modulo your range biases the result, because the range rarely divides evenly into the source's size, leaving the lower numbers slightly more likely. This page avoids both: values come from the operating system's cryptographic entropy pool, and any draw landing in the biased tail is discarded and redrawn rather than folded back in. For a dice roll nobody would notice; for a prize draw or a randomised sample, it's the difference between fair and defensible and merely close.
What else can you check?
These tools all work on the same connection and address data — pick whichever question you actually have.
Want to see the full path to a site?
DNS, redirects, every hop, the CDN, TLS and the origin server.
Want to know your public IP?
See your IPv4 and IPv6 addresses, location, ISP and ASN.
Want to check your tower & route?
Live ping, speed, DNS, traceroute and a map of nearby points.
Want to ping from around the world?
Real latency from real probes across 12 countries, live on a map.
Want to locate any IP address?
City, region, country and coordinates for any public IP.
Want to know if an IP is risky?
Proxy, VPN, Tor, hosting and abuse-report indicators.
Want to know if you're blacklisted?
Check an address against major spam and abuse DNSBLs.
Want to know who owns an IP?
Network owner, ASN, CIDR range and abuse contact.
Want to explore an AS number?
Announced prefixes, BGP neighbours and registry details.
Want to test your connection speed?
Measure real download, upload, ping and jitter.
Want to see what changed?
Word-level diff between two blocks of text or code.
Want to know if a DNS change is live yet?
Compare answers from five independent public resolvers.
Want to verify a domain's nameservers?
Direct authoritative checks, glue records and SOA serials.
Want to check a domain's DNSSEC setup?
DNSKEY, DS records, signature expiry and real validation.
Want to see the hop-by-hop path to a server?
A real traceroute from a genuine probe anywhere in the world.
Want to know if a server port is open?
A real TCP connection attempt - open, closed or filtered.
Want to measure latency to a server?
Real connect timing - min/avg/max, jitter and connection loss.
Want a clean URL slug from a title?
Real transliteration, stop words and batch mode.
Want to find and replace across a document?
Regex, capture groups and a live preview before you commit.
Want to find the invisible character?
Code points, escapes, bytes and hidden-character detection.
Want to escape text for HTML?
Minimal, named or numeric entities, attribute-safe.
Want to strip emoji cleanly?
Whole clusters - no half-flags or stray modifiers left.
Want to spot repeated words?
Frequency, density and accidental doubles like "the the".
Want to know if a URL is cached?
Two requests prove whether your CDN is really caching it.
Want to see what a site knows about you?
Storage, cookies, tokens and what your browser actually cached.
Want to run that check on any site?
One-click bookmarklet reads storage and tokens where they live.
Want to know who your site talks to?
Renders the page and names every outside company it contacts.
Is your site one address or four?
www, non-www, http and https - which serve, which redirect.
Need to build an Authorization header?
Basic, Bearer, API key, Digest and AWS SigV4 - signed in your browser.
Want to tidy up a messy SQL query?
Beautify, minify, lint and convert keyword casing for six dialects.
Need to work out a percentage?
Nine calculators covering every way a percentage gets asked.
Want to work out a rise or a raise?
Increases, growth, compounding and CAGR, with the working shown.
Want to work out a discount or a drop?
Discounts, stacked sales and depreciation, with the working shown.
What is actually on that page?
Words, reading time, readability, every image, embed and link.
Need a favicon that works everywhere?
Every size, a real multi-resolution .ico, and the tags to paste.
What headers does a site send back?
Every response header on every redirect hop, explained.
Need to test a regular expression?
Live matches, capture groups, replace preview and code snippets.
Need a JPG as a PNG?
Batch convert in your browser, with optional transparent background.
Need somewhere to jot things down?
Private notes, links, to-dos and reminders saved in your browser.
Need just some pages of a PDF?
Split by page, range or chunk, or extract the pages you pick.
What is hiding inside that image?
EXIF camera settings, GPS tags, colour palette and web checks.
Random Number FAQ
Are both the minimum and maximum included?
Yes. The range is inclusive at both ends, so 1 to 6 can produce 1 and 6 as well as everything between.
What does "No repeats" do?
It draws without replacement, like pulling numbered balls from a bag. Because that requires at least as many possible values as numbers requested, you'll get a clear error rather than an infinite loop if you ask for 100 unique numbers between 1 and 10.
Can I use this for a prize draw or giveaway?
Yes — the sampling is genuinely unbiased and cryptographically sourced, which is more than most draw tools can say. For anything with legal or financial weight, record your method and the result, since no browser tool can prove to a third party when it was run.
Is the result different every time?
Yes. There's no seed and no way to reproduce a previous run — each draw pulls fresh entropy from the operating system. If you need reproducible pseudo-randomness for testing, you want a seeded generator in your own code, not this.
How many numbers can I generate at once?
Up to 10,000 per run. Beyond that the browser spends longer rendering the list than generating it, and a download is a better fit than an on-screen grid.