Learn how to generate random passwords locally, choose character sets, estimate entropy and avoid common password-creation mistakes.
Generate locally
Tervilo generates the password in the browser so the generated value does not need to be sent to a server.
Length matters
Longer passwords generally create a much larger search space. Randomness and unpredictability matter in addition to length.
Character sets
Adding lowercase, uppercase, numbers and symbols increases the possible character pool. Excluding characters can improve usability but reduces the possible combinations.
Ambiguous characters
Characters such as O/0 and l/1 can be visually confusing. Excluding them can help when a password must be transcribed manually, although it reduces the available character pool.
No repeated characters
This option can be useful for special situations but can reduce the possible password space when the requested length approaches the character-set size.
Password hygiene
Use unique passwords, store them in a reputable password manager and enable multi-factor authentication where available. Never reuse an important password across services.
What makes a generated password stronger?
Randomness and length are the important foundations. A password chosen from a large character set but generated predictably is not equivalent to a truly random password.
Example of search space
If an ideal generator chooses each character independently from a set of 64 possibilities, a 12-character password has 6412 possible combinations. This illustrates why increasing length can have a large effect.
Safer everyday practice
Use a unique credential for each important service, store it in a reputable password manager and enable multi-factor authentication where available. Never publish or share a password simply because it was generated by a trusted tool.
Length Usually Matters More Than Complexity Rules
Longer random passwords generally provide a larger search space. Adding character types can increase the possible combinations, but a short predictable password is not made strong simply by adding a symbol.
Entropy and Search Space
If each character is independently selected from a pool of N possible characters and the password has L characters, the idealized search space is N raised to L. Real security also depends on how the generator creates randomness.
Example
If an ideal generator chooses each character independently from 64 possibilities, a 12-character password has 6412 possible combinations. This illustrates why increasing length can have a large effect.
When to Use a Passphrase
For passwords that must be remembered rather than stored in a password manager, a long randomly generated passphrase can be easier to handle than a short complex password. Avoid predictable quotations or familiar phrases.
Local Generation and Privacy
A browser-based generator can create the password locally, reducing the need to send the generated value to a server. Users should still inspect the site's implementation and avoid entering an existing secret into a generator.
Password Manager and Multi-Factor Authentication
Use a unique credential for every important service, store generated credentials in a reputable password manager and enable multi-factor authentication where available.
Do Not Reuse Generated Passwords
A password that is strong for one service becomes a liability if it is reused elsewhere and another service is compromised. Generate a separate credential for each account.
Use the Tervilo Password Generator
Use the Tervilo Password Generator to generate random passwords locally with configurable length and character sets.