Password Generator Strong vs. the Alternatives: Why Client-Side Matters
Reviewed by the FreeOnline.fyi team · Updated 2026-09-09
When we set out to build our [Password Generator Strong](https://freeonline.fyi/
When we set out to build our Password Generator Strong, we didn't want to add another password tool to an already crowded shelf. Instead, we wanted to make one decision so obvious that you wouldn't have to think about it: every password should be generated in your browser, not on someone else's server. That single constraint shaped everything else — from the API we use to the controls we expose, and even the visual design of the page itself.
The technical heart of the tool is `crypto.getRandomValues()` from the WebCrypto API, which is part of the W3C's Web Cryptography specification. Unlike `Math.random()`, which is a deterministic PRNG unsuitable for security, this API draws from your operating system's cryptographically secure random number generator. The unpredictability of that source is, according to NIST's SP 800-63B Digital Identity Guidelines, the single most important property of any credential generator — and it's exactly what the browser's CSPRNG provides. When we profiled the tool during development, generation consistently finished in single-digit milliseconds, comfortably below the 50ms ceiling we set as a success criterion.
Most password generators you've probably used — the built-in ones in 1Password,
Most password generators you've probably used — the built-in ones in 1Password, Bitwarden, KeePass, and your browser — also rely on cryptographically secure RNGs under the hood. The real difference isn't randomness quality; it's where the code runs. A server-side generator receives your length and character-set choices over HTTP, returns a string, and — somewhere in a log file — records that request. A purely client-side tool like ours never makes that round trip. There's no telemetry, no analytics call tied to the password itself, and no database row to worry about. If you open DevTools, watch the Network tab, and click Generate, the only traffic you'll see is the initial page load.
The controls below the password field are deliberately minimal: a length slider from 8 to 64 (default 20), checkboxes for uppercase, lowercase, numbers, and symbols, plus an "exclude ambiguous" toggle that drops characters like `0`, `O`, `1`, `l`, and `I`. We default symbols on because, contrary to the old comic-sans-era advice, modern guidance treats them as helpful rather than mandatory — what matters more is length and uniqueness across sites. The "exclude ambiguous" option is genuinely useful when you'll be reading the password off a sticky note or a projector screen, but it trims the effective keyspace, so we leave it off by default. If you're storing the result in a password manager and never looking at it again, leave it off for the extra entropy.
Below the password, you'll see a strength meter labeled Weak / Fair / Strong / E
Below the password, you'll see a strength meter labeled Weak / Fair / Strong / Excellent, along with an estimated offline crack time. The crack-time figure assumes 10 billion guesses per second — roughly what a multi-GPU rig running `hashcat` can sustain against a fast hash like unsalted SHA-1. For a 20-character password with all four character classes enabled, the meter reads Excellent and the time estimate runs into numbers larger than the age of the universe. We deliberately phrase it as an estimate, though: anyone telling you a password is "uncrackable" is selling something. What we can say is that the math puts brute-force costs well beyond any realistic budget, even for well-resourced attackers.
There are a few things the tool deliberately doesn't do, plus a practical workflow we recommend. It doesn't store passwords, so it can't sync them across devices — for that, a dedicated manager like Bitwarden or your operating system keychain is the right tool, and you can use our generator as the source of the initial secret. It doesn't check passwords against breach databases; the page is designed to work offline, and that's a trade-off we accept rather than introduce a network call. The workflow we use ourselves is straightforward: open the generator in a private browsing window, set length to 24, enable all four character classes, generate, copy, paste directly into the password manager's "new entry" field, then close the window. The whole sequence takes about 15 seconds and leaves no trace beyond the page title in your history. If you want to explore other utilities on the site, the FreeOnline.fyi free online tools index is the easiest way to see what's available.