Generate a NanoID

Generate a compact random ID from a URL-safe alphabet.

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ToolNanoID Generator
Input
Output
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How it works

Cryptographically strong random bytes are mapped to the selected alphabet with rejection sampling, producing the requested length. The default alphabet avoids characters that need URL escaping.

  • Twenty-one characters balance compactness and collision resistance.
  • Alphabet and length remain explicit because they change the ID space.

Worked example

Default NanoID
Generate a 21-character NanoID with the default alphabet
Input
											Length: 21
Count: 1
Alphabet: ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_-
Output
												Bisas68L0xcyRld2iBRQj

When to use this

Temporary client records, URL slugs, and public database keys generate Nano IDs.

Edge cases

  • A custom alphabet changes collision probability.
  • Reducing the character count shrinks the available combinations sharply.
  • Random output is not authorization without access control.

References