Password Strength Checker Online is a free, browser-based developer tool from PromptSpace. Check password strength, entropy, and estimated crack time in real-time. 100% browser-based — your password never leaves this page. Free. It works entirely in your browser — no signup, no upload, and no data ever leaves your device.
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Password Strength Checker Online is a free, browser-based developer tool. Check password strength, entropy, and estimated crack time in real-time. 100% browser-based — your password never leaves this page. Free. No signup, no installation required — everything runs in your browser. Your data never leaves your device.
Password Strength Checker Online runs entirely as client-side JavaScript in your browser — no server round-trip, no rate limits, no telemetry. Enter your input, click the action button, and results are computed locally and returned instantly.
Yes. All computation is client-side — your input never leaves your device. That said, browser DevTools and extensions can still read what you paste on any page, so use a private/incognito window if you're working with a production secret.
After the page has loaded once, Password Strength Checker Online works offline because all logic ships as JavaScript. If your browser has service workers enabled you can even bookmark it and use it on a plane or in an air-gapped environment.
A UUID (Universally Unique Identifier) is a 128-bit random ID like a1b2c3d4-e5f6-7890-abcd-ef1234567890. It's used when you need a globally-unique key for a database row, event, request trace, or file — without coordinating with a central server. UUID v4 (random) is the default; use v7 if you need timestamp-sortable IDs.
Paste your JWT into the JWT Debugger. It splits the token into header, payload, and signature, Base64-decodes each part, and pretty-prints the JSON claims (sub, exp, iat, iss). Signature verification requires the public key — the decoder shows the algorithm from the header so you know which key format to use.
Use the Password Generator: pick a length (16+ recommended), enable symbols and numbers, and click Generate. The tool uses the browser's crypto.getRandomValues API for cryptographically secure randomness — the same primitive used by password managers.