# Strong Password Generator

> Generate strong random passwords and passphrases instantly. Cryptographically secure, 100% client-side privacy, entropy meter, bulk mode up to 20 at once.

- Page URL: https://itinsighthub.com/password-generator/
- Markdown variant of this page: append `?format=md` to any URL on this site or send `Accept: text/markdown`.
- Full site index for AI assistants: https://itinsighthub.com/llms.txt
- Full site export: https://itinsighthub.com/llms-full.txt

# Password Generator

This generator builds random passwords and passphrases inside your browser with cryptographically secure randomness — nothing you see is ever sent over the network or logged. A strong password is at least 16 characters long and mixes upper-case letters, lower-case letters, digits and symbols.

## Your password generated in your browser

(Va90Nek9~lUeLx3

Excellent · 101 bits of entropy · effectively uncrackable offline

Bulk results (1)
dxFgEPksW5-dU9#)

This example was generated server-side this time only. With JavaScript enabled, every password on this page is created locally on your device and never transmitted.

## How it works

Every password comes from `crypto.getRandomValues()`, the browser's cryptographically secure random number generator — the same primitive TLS keys are built on. Two implementation details matter:

- **No modulo bias.** Naive generators compute `random() % poolSize`, which makes some characters slightly more likely. This tool uses rejection sampling: values outside the largest usable multiple of the pool size are discarded, so every character is exactly equally likely.
- **Every requested character class is guaranteed.** One character is drawn from each enabled set, the remainder fills from the combined pool, and a Fisher–Yates shuffle erases the positions — so a 16-character password always contains your chosen mix without predictable placement.

### The entropy math behind the strength meter

Entropy in bits equals `length × log₂(pool size)`. The pools used here hold 26 letters per case, 10 digits and 16 symbols:

| Configuration | Pool | Entropy at length 16 |
| --- | --- | --- |
| Lower only | 26 | 75 bits |
| Lower + digits | 36 | 83 bits |
| Mixed case + digits | 62 | 95 bits |
| All classes (default) | 78 | 101 bits |
| Passphrase, 6 words (this wordlist) | 272 per word | 48.5 bits |
| Passphrase, 6 words + two-digit suffix | 272 × 100 | 55.2 bits |

Meter labels follow offline-cracking reality against fast GPU hashes: below **48 bits** is *Weak* (cracked in hours), **48–71** *Fair*, **72–95** *Strong*, and **96+** *Excellent*. Each additional word in a passphrase adds a flat 8 bits because the embedded wordlist holds exactly 272 entries.

## Where password generation runs

Most online generators POST your password to a server before showing it to you; it then transits logs, proxies and analytics. Here the entire algorithm ships to you as static JavaScript and executes locally. The server renders only a throwaway example for visitors with JavaScript disabled. After the page loads, generation continues to work with the network disconnected. **Your password never exists anywhere but your device.**

Pair the result with a password manager, enable two-factor authentication wherever it matters, and never reuse passwords across sites — reuse turns any single breach into a credential-stuffing campaign against every other account with that email.

## Related tools

Hardening other parts of your stack? Try the [cron expression generator](https://itinsighthub.com/cron-generator/) for scheduled jobs, the [UUID v4 generator](https://itinsighthub.com/uuid-generator/) for identifiers and API keys' neighbors, or the [Unix timestamp converter](https://itinsighthub.com/timestamp-converter/) when auditing logs. Networking reference work lives in the [common ports cheat sheet](https://itinsighthub.com/common-ports/).

## Frequently asked questions

**What makes a password strong?**

Length first, then unpredictability. A strong password today is at least 16 characters drawn randomly from a large alphabet (upper-case letters, lower-case letters, digits and symbols). Human-invented patterns like Password1! or hunter2 substitutions fail both tests: attackers run dictionaries with mangling rules at billions of guesses per second. Randomness plus length is exactly what the entropy calculation measures.

**Is this password generator safe to use?**

Yes. Generation runs entirely in your browser using crypto.getRandomValues(), and no password is ever transmitted, logged or stored — the server cannot know what you generated. You can verify this yourself: load the page, disconnect from the network, and keep generating passwords.

**How long should my password be?**

16 characters with all character classes (~101 bits) is a solid default for anything protected by a rate-limited login form. Use 20+ characters for high-value accounts like email, cloud consoles and password managers. For systems that forbid symbols, compensate with more characters: 20 mixed-case-and-digit characters give ~119 bits.

**Are passphrases better than passwords?**

They trade raw entropy per character for memorability. Six random words from this site's 272-word list carry about 48.5 bits (55.2 with the two-digit suffix) — enough where a human must remember and type them (disk encryption, master passwords), provided you add more words rather than 'clever' tweaks. For accounts unlocked by a password manager anyway, random characters win because you never have to remember them.

**What does 'exclude ambiguous characters' do?**

It removes look-alike characters — i, l, 1, L, o, 0 and O — from the pool so nobody can misread a dictated or handwritten password. The cost is small: excluding them shrinks each letter/digit pool slightly and reduces entropy by roughly 4% at the same length, which you can offset by adding one character.

**How is password strength calculated here?**

The meter reports Shannon entropy: length multiplied by log₂ of the pool size (for passphrases: words times log₂ of the 272-word list, plus 6.64 bits for the optional two-digit suffix). It estimates how hard the search space is for an attacker who knows exactly how the password was built — the correct worst-case assumption.

---

© 2026 ITInsightHub · [About](https://itinsighthub.com/about/) · [Contact](https://itinsighthub.com/contact/) · [Privacy](https://itinsighthub.com/privacy/)