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NanoID Generator

Generate short, URL-safe IDs with custom length and alphabet. Great for slugs, tokens, and refs.

Alphabet

Default is URL-safe; customize as needed.

Presets:|
Generation mode
Shortcuts: G generate · C copy · R reset
Generated IDs
IDs will appear here after generation.
Length: 10 · Count: 5 · Mode: NanoID compatible · Alphabet: 64 chars

History

Last 5 runs

No history yet. Generate a set to save it here.

Security & collision math

Entropy bits

60.00

Length 10 × log2(64)

Collision probability

<0.01%

Birthday bound for 5 IDs

Notes

Moderate entropy; avoid long-lived secrets or auth tokens.

Collision math uses a simple birthday approximation with total space = alphabetSize^length.

How to use

  1. Pick length (4–32) and count (1–50); choose an alphabet or use presets.
  2. Add prefixes, suffixes, grouping separators, or case transforms for consistent formatting.
  3. Enable “Unique IDs only” for best-effort uniqueness (more reliable with larger alphabets and lengths).
  4. Generate, then copy in TXT/CSV/JSON/NDJSON or download the file.

FAQ & privacy

Does this run locally? Yes. IDs are generated with Web Crypto in your browser.

When do collisions happen? Short lengths or tiny alphabets can collide; increase length/alphabet size or use “Unique IDs only.”

Why NanoID? Short, URL-safe IDs with good collision resistance for slugs, tokens, and references.