Password Strength Checker: How Long Would It Take to Crack Your Password?

You created what you thought was a clever password. Mix of uppercase and lowercase, threw in some numbers, even added an exclamation point. It looks secure. But is it?

Most "strong-looking" passwords are weaker than they appear. The substitutions feel random to you, but they follow patterns that crackers exploit every day.

Let's find out how your password actually holds up.

How Password Cracking Actually Works

Before testing your password, you need to understand what you're defending against.

Brute Force Attacks

The most straightforward method: try every possible combination.

• Speed: Modern GPUs can test 10+ billion password hashes per second
• Weakness: Exponentially slower as password length increases
• Defense: Long passwords (16+ characters)

Dictionary Attacks

Instead of random combinations, try known words and common passwords.

• Speed: Millions of common passwords tested in seconds
• Weakness: Cracks any password using dictionary words or common patterns
• Defense: Avoid real words, use random generation

Rule-Based Attacks

Take dictionary words and apply mutations:

• Capitalize first letter

• Add numbers at the end

• Replace letters with symbols (@ for a, 0 for o)

• Add years (2024, 2025, 2026)

• Combine two words

• Speed: Multiplies dictionary effectiveness by thousands

• Weakness: Cracks "clever" passwords like P@$$w0rd123!

• Defense: True randomness, no human patterns

Rainbow Tables

Pre-computed hashes for millions of passwords. Instead of cracking, just look up the hash.

• Speed: Near-instant for unsalted hashes
• Weakness: Only works if your exact password is pre-computed
• Defense: Long random passwords (too many to pre-compute)

Credential Stuffing

Not cracking at all — using passwords from previous breaches.

• Speed: Instant if your password was breached elsewhere
• Weakness: Works when passwords are reused
• Defense: Unique password for every account

Understanding Password Entropy

Entropy measures password randomness in bits. More bits = exponentially more guesses required.

The Formula

Entropy = log₂(possible characters ^ password length)

Entropy by Password Type

What Entropy Means in Practice

*Assuming 10 billion guesses per second (high-end GPU cluster)

The Catch: Patterns Destroy Entropy

Theoretical entropy assumes true randomness. Human-created passwords have far less actual entropy:

• "Password1!" has 52 bits theoretical entropy
• Actual entropy: ~10 bits (common pattern, cracked instantly)

Real entropy depends on unpredictability, not character count.

Time-to-Crack Estimates

Here's how long different password types resist a modern cracking rig (10B guesses/second):

Weak Passwords (Don't Use These)

Medium Passwords (Better, Not Great)

Strong Passwords (Use These)

What Our Strength Checker Analyzes

Our password strength checker evaluates your password across multiple dimensions:

Length

The single most important factor. Every additional character doubles the difficulty.

Character Diversity

Using uppercase, lowercase, numbers, and symbols expands the search space — but only matters if selection is random.

Pattern Detection

We scan for:

• Keyboard patterns (qwerty, 123456, asdfgh)
• Repeated characters (aaa, 111)
• Sequential characters (abc, 123)
• Common substitutions (@ for a, 0 for o)
• Dictionary words
• Date patterns (MMDDYYYY, YYYY)

Known Breach Check

We check against databases of breached passwords. If your exact password has leaked before, it's compromised regardless of complexity.

Contextual Analysis

Passwords containing common structures lose points:

• Capital first, rest lowercase
• Numbers only at the end
• Single symbol at the end
• Year appended

How to Interpret Your Results

Score: Weak (0-40)

Your password could be cracked in seconds to minutes. Common issues:

• Too short
• Uses dictionary words
• Follows common patterns
• Has appeared in breaches

Action: Generate a new password immediately.

Score: Fair (41-60)

Your password would take hours to days to crack. Usually means:

• Decent length but predictable structure
• Some patterns detected
• Uses words with modifications

Action: Consider upgrading for important accounts.

Score: Strong (61-80)

Your password would take months to years to crack. Typically:

• 12+ characters
• Good randomness
• No dictionary words or common patterns

Action: Acceptable for most accounts. Excellent for low-risk logins.

Score: Very Strong (81-100)

Your password is effectively uncrackable with current technology. Characteristics:

• 16+ characters
• High randomness
• No detectable patterns
• Not in breach databases

Action: Perfect for high-security accounts.

Improving a Weak Password

❌ Wrong Approach

Taking "password" and making it "P@$$w0rd123!"

This feels more secure but:

• Common substitution patterns are in cracking rules
• Adding 123! at the end is predictable
• Total entropy gain: minimal
• Crack time: still seconds

✅ Right Approach

Use our password generator to create: Kj7#mZq9!vXnL2@pW

Or our passphrase generator for: glacier phantom butter notebook

Both are:

• Truly random (high real entropy)
• No patterns for rules to exploit
• Resistant to dictionary attacks
• Practically uncrackable

Security Best Practices

Use a Password Manager

You can't memorize 100+ strong random passwords. Let software handle it:

• Generate unique passwords for every account
• Store them encrypted
• Auto-fill when needed
• Remember only your master password

Enable Two-Factor Authentication

Even the strongest password can be phished or leaked in a breach. 2FA adds a second barrier:

• Authenticator apps (Google Authenticator, Authy)
• Hardware keys (YubiKey)
• SMS codes (better than nothing)

Monitor for Breaches

Check Have I Been Pwned periodically. If your email appears in a breach, change passwords on affected accounts immediately.

Don't Reuse Passwords

One password per account. No exceptions. A breach at one site shouldn't compromise everything else.

FAQ: Password Strength Questions

How long should my password be?

Minimum 12 characters for moderate security, 16+ characters for strong security. Every additional character doubles cracking difficulty.

Is a password with symbols stronger than one without?

Only if the password is also long and random. Adding "!" to "password" doesn't help. Adding "!" to a 16-character random string adds meaningful entropy.

Does my password need numbers and symbols?

Not necessarily. A 20-character lowercase password has more entropy than a 10-character password with symbols. Length matters more than character variety.

What if my password passes this test but is still weak?

Strength checkers can't detect everything. If your password has personal meaning (pet names, dates, inside jokes), it may be guessable through social engineering even if it looks random.

How often should I check my password strength?

Check new passwords before using them. Re-check existing passwords if you hear about a breach at a service you use.

Check your password strength: Password Strength Checker →
Generate a secure password: Password Generator →

Our strength checker runs entirely in your browser. Passwords are never transmitted or stored.