ToolBrainy

Password Strength Checker

Test how strong your password really is — with an estimated crack time and tips to make it stronger.

Enter a password
At least 8 characters
12 or more characters
Lowercase letter
Uppercase letter
Number
Symbol
Not a common password
No obvious patterns

About This Tool

The ToolBrainy Password Strength Checker rates any password in real time and shows roughly how long it would take an attacker to crack it. As you type, it measures length, character variety, and common weak patterns, then gives you a clear verdict from Very Weak to Very Strong.

Everything happens inside your browser using JavaScript — your password is never typed anywhere but this page, never stored, and never sent to a server. Close the tab and it is gone.

How to Use

1
Type or paste a password

Enter the password you want to test. Use the eye button to reveal it if you want to double-check what you typed.

2
Read the strength verdict

The coloured meter and label update instantly, along with an estimate of how long it would take to crack.

3
Follow the tips

The checklist and suggestions show exactly what to add — more length, mixed cases, numbers, or symbols — to make it stronger.

Why Use This Checker?

100% private

Your password never leaves your browser. No network requests, no logging, no storage.

Crack-time estimate

See a realistic guess of how long a fast offline attack would need to break it.

Clear checklist

Instantly see which best-practice rules your password already meets and which it misses.

Actionable tips

Get specific, plain-language advice on how to make a weak password stronger.

Live as you type

Results update on every keystroke — no submit button, no waiting.

Common-password aware

Flags well-known passwords and obvious sequences that look complex but are easy to guess.

Use Cases

New account sign-ups

Check a password before creating an account to make sure it is genuinely secure.

Audit old passwords

Test passwords you have reused for years to decide which ones need replacing.

Teach good habits

Show family, students, or colleagues why length and variety matter.

Set policy standards

Gauge whether the passwords your team uses would meet a strong baseline.

Verify a generated password

Confirm that a password from a generator is as strong as you expect.

Build a passphrase

Experiment with longer phrases and watch the strength climb in real time.

Frequently Asked Questions

Is it safe to type my real password here?

Yes. The check runs entirely in your browser with JavaScript. Your password is never sent over the internet, never stored, and vanishes the moment you clear the box or close the tab.

How is the strength calculated?

It estimates entropy from the password's length and the mix of character types (lowercase, uppercase, numbers, symbols), then reduces the score if it detects common passwords or predictable patterns like repeats and sequences.

What does the crack-time estimate mean?

It is a rough guess of how long a fast offline attacker trying billions of guesses per second would need to try every combination. It is a guideline, not a guarantee — real-world speed varies.

What makes a strong password?

Length matters most. Aim for at least 12–16 characters, mix upper and lower case, numbers and symbols, and avoid names, dictionary words, and predictable sequences. A long random passphrase is both strong and easy to remember.

Why is my complex-looking password rated weak?

Passwords like "P@ssw0rd" or "Qwerty123!" look complex but are on every attacker's guess list. Predictable substitutions and keyboard patterns are cracked almost instantly, so the tool marks them down.

Should I use a password manager?

Absolutely. A password manager generates long, unique, random passwords for every site and remembers them for you — the single best upgrade you can make to your online security.

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