Password Generator
Generate random passwords with the browser cryptographic random-number API and estimate theoretical strength.
Formula and sources updated · Data sources · 1View algorithm, constants and default inputs (JSON)
About this calculator
Generate passwords locally in your browser using its cryptographic random-number API. Entropy is a theoretical estimate from length and the selected character pool; the crack-time label assumes 10 billion guesses per second and is not a prediction of real-world security. Use a password manager and unique passwords.
Worked example
calculated with the default values below
Password length 16 characters · How many passwords 5 · Allow uppercase letters Yes · Allow digits Yes · Allow symbols Yes · Avoid look-alike characters Yes Generated passwords — · Characters available 82 · Entropy 101.7 bits · Possible combinations 10^31 · Strength Very strong · Time to crack at 10 billion guesses a second longer than the age of the universe · What this means Passwords are generated only in the browser. Entropy and crack-time labels are theoretical estimates.
Data sources
Disclaimer
These calculators give general date results. Public holidays, working-day conventions and time-zone rules are set locally and change, so confirm against the official calendar for anything legally or contractually binding.
Implementation source
This record describes the implementation used by this page. It is not independent validation. External references, when available, support only the stated formula or definition; estimates and custom rules retain their own assumptions.
Formula and variables
H = L log₂(P); combos = P^L
- L
- Password length (4-64)
- P
- Pool size (selected character sets)
- H
- Entropy (bits)
- t_c
- Crack time (seconds)
Generated in the browser with a cryptographic random-number API. Crack-time assumes 10 billion guesses per second and is only theoretical.
Frequently asked questions
Are the generated passwords suitable for real accounts?
The generator uses the browser cryptographic random-number API, but strength labels are estimates and depend on the actual attack model. Use a password manager, choose a unique password for each account, and avoid sharing or storing generated values in URLs.