Random String Generator
Random identifiers from a chosen alphabet. Free, and runs entirely in your browser — nothing you enter is uploaded, stored or sent to a server.
About Random String
Random identifiers from a chosen alphabet, generated with crypto.getRandomValues. The alphabet matters as much as the length: hex for keys that will be read by machines, Base58 for values people retype (it drops 0, O, I and l), URL-safe for anything that ends up in a path or a query string.
Pool size and the resulting entropy per string are reported, so you can see whether a 16-character token is actually enough for what you are protecting.
Where it helps
- Cryptographically secure randomness, never
Math.random. - Seven preset alphabets plus a custom one for a specific format.
- Reports entropy per string so length can be chosen with evidence.
- Up to 100 strings at once, for seeding fixtures or bulk keys.
Limits
- Nothing is stored, so a generated secret you do not save is gone.
- Character selection uses modulo over random values, which is fine for identifiers but not for scenarios demanding perfectly uniform sampling.
- A custom alphabet with repeated characters silently skews the distribution.
- A random string is not a signed token: it carries no claims and cannot be validated without a lookup.
Frequently asked questions
How long should an API key be?
At least 128 bits of entropy — 32 hex characters, or 22 URL-safe characters. The entropy row tells you where you stand.
Why choose Base58?
It removes the characters people confuse when reading aloud or retyping: 0, O, I and l. Bitcoin addresses use it for the same reason.
Is this the same as the Password Generator?
The randomness is equally strong. The password tool is shaped around character classes and human-facing rules; this one is shaped around alphabets and machine identifiers.
Can I use these as session identifiers?
Yes, at sufficient length — 128 bits or more of entropy, stored server-side and compared in constant time.
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