Generate secure random integers, random strings and v4 UUIDs with one privacy-first crypto tool. Pick ranges, alphabets and batch sizes offline.
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Quick answer: Random Number, String & UUID Generator — Numbers, strings & UUIDs Free, no signup, runs in your browser. See below for the interactive tool, 4-step guide and FAQs.
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Three views share one tab bar. Numbers rolls unbiased integers in any range with optional uniqueness, Strings builds keys, salts and invite codes from chosen alphabets, and UUIDs mints RFC 4122 version 4 identifiers in bulk. For example, 5 unique winners from 1 to 200 might read 7, 42, 98, 150 and 189, while a 32-character token looks like aZ8kQ2mT9xR4vB7nC1dF6hJ3sP5wE8y.
Yes. Every integer, character and UUID draws from window.crypto with rejection sampling, never Math.random, so no sequence is predictable and remainders never skew toward small values. A 32-character alphanumeric token carries about 190 bits of entropy, adding symbols lifts it near 209 bits, and 1000 version 4 UUIDs collide with odds around 1 in 10 to the 36th.
Turn on the unique toggle and the Number view reshuffles like a lottery drum, guaranteeing no repeats as long as the count fits the range. Asking for 150 unique values from 1 to 100 is rejected with a clear message instead of silently failing. Leave unique off for dice-style simulations and bootstrap sampling where repeats are expected.
Numbers span any range up to a million and batch up to 1000 values. Strings run from 8 to 128 characters, drawn from lowercase, uppercase, digits and symbols, up to 10000 at a time. UUIDs generate up to 500 per run with an optional uppercase toggle. Every batch copies as a comma list or newline block for spreadsheets, .env files and fixtures.
Pick Numbers for raffles, seating and test fixtures, Strings for API tokens, salts and invite codes, and UUIDs for distributed database keys that must not collide when shards merge. UUIDs suit systems where a central counter would leak growth or stall on coordination, while a short random string reads better on a printed coupon. All three stay on device, so nothing is logged or posted.
Nothing is uploaded. Each view computes locally in your browser and clears when the tab closes, so unreleased keys and draw results stay private. Results expose single and bulk copy buttons that place a comma list, a newline block or a single value on your clipboard, ready to paste into Postgres tables, JSON fixtures or a password vault.
Three views centralize trustworthy randomness in one offline page. Numbers rolls unbiased integers with optional uniqueness for raffles and fixtures, Strings builds tokens and salts from selectable alphabets, and UUIDs mints standards-compliant identifiers in bulk. Five winners from 1 to 200 might read 7, 42, 98, 150 and 189; a 32-character key looks like aZ8kQ2mT9xR4vB7nC1dF6hJ3sP5wE8y; and an ID reads 550e8400-e29b-41d4-a716-446655440000. Reference table: Numbers equal fair draws, Strings equal secrets, UUIDs equal database keys, each copied as a list or block.
Randomness comes from window.crypto, which harvests operating-system entropy, and rejection sampling discards out-of-range draws so every value is equally likely. Modulo alone would bias small numbers upward, so the code retries until a draw lands inside the allowed band. Entropy grows with alphabet size and length: 16 alphanumerics give about 95 bits, 32 climb near 190 bits, and a version 4 UUID packs 122 random bits while reserving six for version and variant markers. Limitation: lengths and batches are capped to keep the browser responsive, and UUIDs are random rather than time-sortable like version 7.
Run a raffle: set 1 to 200, count 5, unique on, and draw 7, 42, 98, 150, 189. Then rotate secrets: pick 32 alphanumerics, count 5, and paste the batch into .env as API_SECRET_1 through _5. Finally seed a database with 500 uppercase UUIDs. Edge case: requesting more unique values than the range allows is blocked, so widen the range or lower the count. Keep generated keys out of shared machines, regenerate rather than reuse a leaked token, and for entropy sizing compare a 16-character string against a 12-word passphrase in the random passphrase generator.