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Free Password Generator Online – Strong Random Passwords & Passphrases | TrenTyx

trentyx@local:~/dev-utilities/password-generator $ run password-generator_

Generate strong random passwords or memorable passphrases using your browser's cryptographic random number generator. Adjustable length, character sets and bulk output, with a live entropy meter. Nothing is sent to a server.

— 0 bits of entropy offline cracking time: —
Password Type
20
Character Sets
Rules
bulk-passwords.txt 0 generated
No batch generated yet — choose a quantity and press Generate Batch.

What Makes a Password Strong?

Password strength is measured in entropy — the number of bits of randomness behind it. Every extra bit doubles the number of guesses an attacker needs. A 12-character password drawn from all four character sets carries roughly 78 bits; the same length using only lowercase letters carries about 56 bits, which is thousands of times weaker. Length contributes more than complexity, which is why a five-word passphrase can beat a short password full of symbols while still being possible to remember.

This generator uses crypto.getRandomValues(), the browser's cryptographically secure random number generator, with rejection sampling so that no character is more likely to appear than any other. Math.random() is never used. Every password is created locally on your device — nothing is transmitted, logged, or stored.

Common Use Cases

  • Account and database credentials — generate a long random string for a service account that no human needs to memorise.
  • Memorable master passwords — use passphrase mode for the one password you must type from memory, such as a password manager vault.
  • Seeding test environments — produce a batch of unique credentials for staging users or fixtures in one click.
  • Wi-Fi and device setup — enable the ambiguous-character filter so the password can be read aloud or typed from a printed card without confusion.

Frequently Asked Questions

Are these passwords really random?

Yes. They come from crypto.getRandomValues(), which is backed by the operating system's entropy pool. The tool also uses rejection sampling instead of the modulo operator, so no character in the pool is statistically favoured over another.

Is my password sent anywhere?

No. All generation happens in JavaScript inside your browser tab. There is no network request, no analytics event carrying the value, and nothing written to storage. Closing the tab discards everything.

Which is better, a random password or a passphrase?

For anything stored in a password manager, use a long random password — you never have to type it. Use a passphrase for the handful of passwords you must remember and type manually, since it reaches high entropy while staying readable.

What does the cracking time estimate mean?

It assumes an offline attack against a fast, poorly protected hash at roughly 100 billion guesses per second, and reports the time to search half the keyspace. Online attacks against a rate-limited login are far slower, so treat the figure as a deliberately pessimistic worst case.

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