voiddo passgen vs passwordsgenerator.net
Both generate passwords online. This page compares entropy reporting, diceware passphrases, CSPRNG implementation, crack-time estimates, and when each tool fits your workflow.
voiddo passgen — use when
- You want to see entropy in bits + estimated crack time for every password
- You need diceware-style passphrases (1,024-word list, 4–8 words)
- You want zero server calls — crypto.getRandomValues() rejection sampling in-browser only
- You want unbiased sampling — rejection sampling eliminates modulo bias
- You need entropy-safe custom character sets for specific policy requirements
- You want no ads, no signup, no rate limits
passwordsgenerator.net — use when
- You need a quick familiar password with a long-established domain
- You want pronounceable passwords — easier to read aloud or type on mobile
- You want bulk password lists with export to plain text or CSV
- Input is non-sensitive and server-side generation is acceptable
feature comparison
| feature | voiddo passgen | passwordsgenerator.net |
|---|---|---|
| random character password | ✓ browser-only CSPRNG | ✓ |
| entropy display (bits) | ✓ per configuration | not shown |
| crack-time estimate | ✓ at 10B guesses/sec | not shown |
| diceware-style passphrases | ✓ 1,024-word list, 4–8 words | not supported |
| rejection sampling (unbiased) | ✓ crypto.getRandomValues() | implementation not disclosed |
| data sent to server | never — browser-only | server-side generation |
| uppercase / lowercase / digits / symbols | ✓ toggleable character sets | ✓ |
| pronounceable passwords | not currently | ✓ |
| bulk password list export | not currently | ✓ plain text / CSV |
| zero external dependencies | ✓ no libraries | not disclosed |
| ads | none | ads present |
| price | free | free |
| account required | no | no |
frequently asked questions
Is voiddo passgen an alternative to passwordsgenerator.net?
Yes. voiddo passgen is a free browser-only password and passphrase generator. It uses
crypto.getRandomValues() rejection sampling so generation is unbiased and nothing is sent to any server. It reports entropy in bits and estimated crack time for every password — features passwordsgenerator.net does not offer. It also generates diceware-style passphrases from a 1,024-word list.Does voiddo passgen send passwords to a server?
No. All generation runs in your browser using
crypto.getRandomValues() rejection sampling — the same CSPRNG the browser uses for TLS. No password or configuration is transmitted over the network after the page loads. You can verify this in DevTools → Network tab: the only outbound requests after load are for fonts and shared CSS.What is entropy in bits and why does it matter for passwords?
Password entropy (measured in bits) is log₂ of the total number of possible passwords for a given length and character set. A 12-character password from a 72-character set has log₂(72¹²) ≈ 74 bits of entropy. Higher entropy means an attacker must test more combinations to crack it by brute force. voiddo passgen displays entropy for every configuration and shows a crack-time estimate at 10 billion guesses per second — a realistic figure for an offline hash attack with a GPU cluster. passwordsgenerator.net does not show entropy or crack-time estimates.
What are diceware passphrases and why are they secure?
A diceware passphrase is a sequence of random words drawn from a fixed word list. voiddo passgen uses a 1,024-word list: a 5-word passphrase gives log₂(1024⁵) = 50 bits of entropy; a 6-word passphrase gives 60 bits. Passphrases are much easier to remember than random character strings while remaining highly resistant to dictionary attacks because the words are chosen randomly, not by meaning. voiddo passgen generates diceware-style passphrases directly. passwordsgenerator.net does not offer passphrase generation.
What is rejection sampling and does it make passwords more random?
Simple modulo-based character selection (randomValue % charsetSize) introduces a small statistical bias when the charset size does not divide evenly into the CSPRNG output range. Rejection sampling discards values that would cause bias and resamples until an unbiased value is found — ensuring every character in the set is equally likely. voiddo passgen uses rejection sampling via
crypto.getRandomValues(). The technique eliminates a class of theoretical weakness and is the approach recommended by NIST SP 800-90A.Is voiddo passgen free?
Yes — completely free with no ads, no signup, no rate limits, and no paywalls. It is part of the 49+ free developer tools at tools.voiddo.com.
Try voiddo passgen — browser-only, entropy display, diceware passphrases, no ads:
open password generator →Feature descriptions based on publicly observable behaviour as of May 2026. Features may change; verify on each tool's own page before making a production decision.