---
title: "Password Strength Checker"
description: "Check password strength. Get crack time estimates, entropy analysis, and improvement tips. 100% client-side — nothing leaves your device."
url: https://findutils.com/security/password-strength-checker/
category: security
---

# Password Strength Checker

Check password strength. Get crack time estimates, entropy analysis, and improvement tips. 100% client-side — nothing leaves your device.

**Use this tool:** [Password Strength Checker](https://findutils.com/security/password-strength-checker/)

## Programmatic access

- REST id `password-strength`: POST https://api.findutils.com/api/tools/password-strength/execute (reference: https://findutils.com/api/password-strength/)
- MCP tool `password_strength` on https://mcp.findutils.com (reference: https://findutils.com/mcp/password-strength/)

## Why Check Your Password Strength?

Weak passwords are the leading cause of security breaches. Our tool analyzes your password against multiple criteria including length, character variety, common password lists, and pattern detection. Get instant feedback on how to make your passwords stronger and protect your accounts.

## Tips for Creating Strong Passwords

- Use a passphrase of four or more random words joined together, such as correct-horse-battery-staple, which is both strong and memorable.
- Never reuse the same password across multiple accounts. A breach on one site exposes every account that shares the same credential.
- Enable two-factor authentication wherever possible. Even the strongest password benefits from a second verification layer.
- Avoid personal information like birthdays, pet names, or addresses. Attackers scrape social media profiles for exactly this data.
- Use a password manager to generate and store unique passwords for every account. You only need to remember one master password.

## Frequently Asked Questions

### Is my password sent to your servers?

No. All password analysis happens locally in your browser using JavaScript. Your password never leaves your device and is not transmitted over the internet.

### What makes a strong password?

A strong password is at least 12 characters long, uses a mix of uppercase, lowercase, numbers, and symbols, and avoids common words, patterns, and personal information.

### How is crack time calculated?

We estimate crack time based on the character set size and password length, assuming a modern GPU capable of 10 billion guesses per second. This is a theoretical estimate for brute-force attacks.

### Should I use a password manager?

Yes! Password managers let you use unique, strong passwords for every account without memorizing them. They're one of the best security investments you can make.

### How often should I change my passwords?

Change passwords immediately if you suspect a breach. Otherwise, use strong unique passwords and enable two-factor authentication rather than changing passwords frequently.

### What is password entropy?

Entropy measures the randomness of a password in bits. Higher entropy means more possible combinations an attacker must try. A 12-character password mixing all character types typically has around 72-80 bits of entropy, which is considered strong.

### Can this tool detect if my password was leaked in a data breach?

This tool focuses on strength analysis. To check whether your password has appeared in a known data breach, use the Password Breach Checker, which cross-references your credential against leaked databases without exposing it.

### Is a longer password always better than a complex one?

Length is generally more impactful than complexity. A 20-character passphrase made of random words is harder to crack than an 8-character password with symbols. However, the best approach combines both length and character variety.

### Does the checker test against common password lists?

Yes. The tool compares your input against a database of commonly used passwords such as 123456, password, and qwerty. If your password matches a known common entry, it is flagged as very weak regardless of length.

### Why does my password show as weak even though it has symbols?

Symbols alone do not guarantee strength. If the password is short, uses predictable substitutions like @ for a or contains dictionary words, it remains vulnerable to rule-based attacks that account for these patterns.

## Related Tools

- [Password Hasher (bcrypt / Argon2id)](https://findutils.com/security/password-hasher/)
- [Password Generator](https://findutils.com/security/password-generator/)
- [Password Breach Checker](https://findutils.com/security/password-breach-checker/)
- [Password Pattern Validator](https://findutils.com/security/password-pattern-validator/)
- [Text Encryption](https://findutils.com/security/text-encryption/)
- [Hash Comparison Tool](https://findutils.com/security/hash-comparison-tool/)
- [MD5 Hash Generator](https://findutils.com/security/md5-hash-generator/)
- [Random Key Generator](https://findutils.com/security/random-key-generator/)