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Private browser-based analysis

Free Password Strength Checker - Fast Browser Tool

Analyze password length, character variety, estimated entropy, common terms, keyboard paths, sequences, repetition, and illustrative crack time directly in your browser.

Check Password Strength See how it works
No password uploads No storage or logging Pattern detection Practical suggestions

Password Strength Checker

Enter a password to receive immediate local analysis. The score is a transparent heuristic estimate rather than a security guarantee.

100% local analysis

Enter a password

You may test an example rather than an active password. Analysis updates automatically as you type.

Not checked 0 / 100
The password remains in this page only. It is not submitted, uploaded, stored, logged, or included in copied analysis.
At least 12 characters
16+ characters preferred
Lowercase character
Uppercase character
Number
Symbol
Good character variety
No obvious pattern

Not checked

Enter a password to view its estimated strength, patterns, entropy, and improvement suggestions.

Estimated entropy 0 bits
Password length 0 characters
Fast offline attack -
Throttled online attack -

Illustrative average search estimates use 10 billion guesses/second offline and 10 guesses/second online. Real attacks can be faster or slower.

Character composition

Lowercase
0
Uppercase
0
Numbers
0
Symbols
0
Other Unicode
0

Pattern findings

  • Waiting for a password.

Suggested improvements

  • Enter a password to receive tailored suggestions.

How this score is estimated

  • Starts with length and estimated character pool entropy.
  • Reduces the estimate for common or predictable structures.
  • Applies safety caps to short, repeated, or sequential passwords.
01
Private by design No password submission or storage
02
Pattern-aware Detects common predictable structures
03
Transparent estimate Explains the factors affecting the score
04
No external library Analysis runs with local JavaScript
Password security explained

Length and unpredictability matter more than complexity alone

A strong password should be long, unique, and difficult to predict. Adding one uppercase letter or number to a common word does not make it secure if attackers are likely to test that variation early.

Password-cracking tools prioritize common passwords, leaked patterns, keyboard paths, dates, repeated characters, and predictable substitutions. That is why this checker applies pattern penalties instead of evaluating character variety alone.

Unique passwords limit breach damage

Even a strong password should never be reused. If one service exposes it, automated credential-stuffing attacks may try the same credentials on email, banking, social media, and other accounts.

Use a password manager and multi-factor authentication

A reputable password manager can create and store long random passwords for every account. Multi-factor authentication adds another barrier if a password is guessed, stolen, or exposed.

Useful security analysis

More than a simple character checklist

Evaluate both theoretical complexity and the predictable patterns attackers are likely to test first.

Private local analysis

The entered password is evaluated inside your browser without server submission, storage, or analytics logging.

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Entropy estimate

See a pattern-adjusted estimate based on length, character pool, uniqueness, and predictable structures.

⌁

Sequence detection

Detect alphabetic, numeric, reverse, and common keyboard paths that can weaken an otherwise complex-looking password.

↻

Repetition checks

Identify repeated characters and repeated chunks that reduce the effective search space for an attacker.

⏱

Attack-time scenarios

Compare illustrative throttled-online and fast-offline estimates while keeping their assumptions visible.

✦

Secure example generator

Generate a 20-character example using cryptographically secure browser randomness and all major character classes.

Three simple steps

How to check password strength

Receive useful feedback without submitting the password to a remote server.

01
Step 1

Enter an example password

Type or generate an example. Avoid testing an active password on devices you do not trust.

02
Step 2

Review the analysis

Inspect the score, entropy estimate, character composition, patterns, and attack-time scenarios.

03
Step 3

Improve account security

Use a unique password manager-generated password and enable multi-factor authentication where available.

Score reference

Understanding the password strength levels

The score combines estimated entropy with practical penalties and safety caps for predictable structures.

Rating
Score
General interpretation
Very Weak
1–20
Extremely short, common, repeated, or highly predictable.
Weak
21–40
Some variation, but insufficient length or obvious patterns remain.
Fair
41–60
Moderate resistance, but further length and unpredictability are recommended.
Strong
61–80
Good estimated resistance with limited obvious predictability.
Very Strong
81–100
Long and difficult to predict, though uniqueness remains essential.
A high score is not proof of safety. A password can still be unsafe if it has been exposed, reused, phished, stored insecurely, or entered on a compromised device.
Security best practices

Build stronger account protection

Password strength is important, but it is only one part of account security.

1

Use a unique password for every account

Password reuse lets a single breach threaten many otherwise unrelated services.

2

Prefer 16 or more characters

Longer passwords generally provide more resistance than short passwords with superficial complexity.

3

Use a reputable password manager

Let a password manager generate, store, and autofill unique random credentials.

4

Enable multi-factor authentication

Prefer authenticator apps, security keys, or passkeys when supported by the service.

Common questions

Password Strength Checker FAQ

What makes a password strong?

A strong password is long, unique, difficult to predict, and not based on common words, personal information, keyboard paths, dates, sequences, or repeated characters. A password manager can create and store unique random passwords.

Does this checker upload or store my password?

No. The analysis runs locally in your browser. The template does not submit, upload, log, store, or include your entered password in copied analysis.

Does this tool check breached-password databases?

No. It compares against a small local list of common passwords but does not contact an online breach database. A separate privacy-preserving breach-check service is required for comprehensive exposure checking.

How accurate are the strength and crack-time estimates?

They are educational estimates, not guarantees. Real attack speed depends on password hashing, hardware, leaked patterns, attacker knowledge, rate limits, and multi-factor authentication.

How long should a password be?

At least 12 characters is a useful baseline, while 16 or more characters is preferable for important accounts. Length should be combined with uniqueness and unpredictability.

Are passphrases secure?

A long passphrase made from several unrelated words can be strong and easier to remember. Avoid famous quotations, song lyrics, predictable phrases, personal details, and reused passphrases.

Should I reuse a strong password?

No. Every account should use a unique password so that a breach at one service cannot expose other accounts. Use a reputable password manager and enable multi-factor authentication where available.

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Check your password strategy privately

Analyze an example, review predictable patterns, and use a password manager to create unique credentials for every account.

Check Password Strength