Password Strength Analyzer

Analyze password security.

freeworks offlinenothing uploaded
Input
Output

About password strength analyzer

Password Strength Analyzer runs in the page as you use it. There is no input to submit and no result to fetch, because the whole thing happens on this side of the wire.

Your input goes into a function and the result comes back out, both inside this tab. There is no round trip and no third party in the middle.

You will find it under Passwords, alongside 7 other tools for the same sort of job.

Calculates entropy, crack time estimates, detects common patterns, keyboard sequences, and repeated characters.

How to use it

01
Start it
Every control is on the tool itself. Keyboard shortcuts, where there are any, are listed beside it.
02
Watch it run
It updates in the page as you go. Nothing is sent anywhere, so it keeps working with the network off.
03
Close when done
Nothing is stored between visits. Reloading gives you a clean start rather than picking up where you left off.

Examples

Weak Password
Analyze a common weak password
Input
password123
Output
=== Password Strength Analysis ===

Password length: 11
Strength: Very Strong (80/100)
Entropy: 56.9 bits
Character pool: 36 characters
Estimated crack time: 76 days (10B guesses/sec)

Character types:
  Lowercase: Yes
  Uppercase: No
  Numbers: Yes
  Symbols: No
  Spaces: No

Recommendations:
  - Use at least 12 characters
  - Add uppercase letters
  - Add special characters
  - Use more character types
Strong Password
Analyze a strong password with mixed character types
Input
Tr0ub4dor&3#Kx!m
Output
=== Password Strength Analysis ===

Password length: 16
Strength: Very Strong (100/100)
Entropy: 105.1 bits
Character pool: 95 characters
Estimated crack time: Centuries+ (10B guesses/sec)

Character types:
  Lowercase: Yes
  Uppercase: Yes
  Numbers: Yes
  Symbols: Yes
  Spaces: No

Questions

Does Password Strength Analyzer work offline?+

Yes. It is JavaScript running in this tab, so once the page has loaded it needs nothing further from the network. Put the machine in flight mode and it carries on. Nothing you do here is sent anywhere, because there is nowhere for it to go.

Does it remember anything between visits?+

No. Reload the page and it starts from nothing. There is no account, no saved state and no cookie holding your last session. That is a deliberate trade: it cannot lose your data because it never keeps any.

Is it accurate?+

Timing comes from performance.now(), the high resolution clock the browser provides, rather than from setInterval, which drifts by a few milliseconds every tick and compounds over minutes. What can still shift things is the browser throttling a tab in the background, so leave it visible if the timing matters.

Does it make a sound?+

Where a sound makes sense, it is generated with the Web Audio API rather than loaded as a file, so there is nothing to download and nothing to block. Browsers refuse to start audio until you have interacted with the page, which is why the first press is what switches it on.

Can I use Password Strength Analyzer on a phone?+

Yes. The controls are sized for touch and the layout collapses to one column on a narrow screen. Bear in mind that a phone locking its screen will suspend the page, and timing stops with it.