This tool runs entirely in your browser — your password is never uploaded, transmitted, or stored anywhere. Still, avoid typing a password you actually use into any web page you don't fully trust; use this to test a similar practice password instead if in doubt.
About Sentinel
Sentinel estimates how strong a password is by checking its length, character variety, and whether it matches known common passwords or simple patterns — then shows the result on a gauge from very weak to very strong. Nothing you type ever leaves your browser.
Features
- Live strength scoring as you type
- Checklist for length, case, numbers, and symbols
- Flags common or leaked passwords and simple patterns
- Rough estimate of offline guessing time
- Show/hide toggle — nothing is logged
- Runs entirely in your browser — nothing is uploaded
How to use it
- Type a password into the field (or a stand-in you don't use elsewhere).
- Watch the checklist and gauge update in real time.
- Use the "Show" toggle to double-check what you typed.
- Aim for "Strong" or "Very strong" before using a password for real.
Strength scale reference
| Category | What it usually means |
|---|---|
| Very weak | Short, common, or an obvious pattern (e.g. "password1") |
| Weak | Some length or variety, but easy to guess or crack quickly |
| Fair | Decent length and mixed characters, no major red flags |
| Strong | Long, varied, and not matched to any common list |
| Very strong | Long and highly varied — resistant to most automated guessing |
Frequently asked questions
How is the strength score calculated?
Sentinel combines password length, the variety of character types used (uppercase, lowercase, numbers, symbols), and checks against a list of very common passwords and simple keyboard patterns. Longer, more varied, less predictable passwords score higher.
Is the crack-time estimate accurate?
It's a rough order-of-magnitude estimate assuming an offline guessing attack, not a precise measurement. Real-world cracking speed depends on the attacker's hardware and the way the password is stored, so treat it as a general guide rather than an exact figure.
Is my password sent anywhere?
No. All checking happens locally in your browser using plain JavaScript — nothing is uploaded, transmitted, or stored on a server.
Should I type my real password into this tool?
Even though nothing leaves your browser, it's good practice to avoid typing real passwords into web pages when you can. Try a password of similar length and structure instead if you want to keep your actual credentials private.