Verificador de Força de Senha

Esta calculadora fornece cálculos instantâneos e precisos nesta área. Insira seus dados e obtenha resultados imediatamente com explicação clara. Esta ferramenta gratuita funciona completamente no seu navegador — sem transferência de dados, sem cadastro necessário.

Cálculos precisos nesta área requerem compreensão das fórmulas e padrões subjacentes. Nossa calculadora aplica os métodos mais amplamente aceitos recomendados por instituições internacionais e consenso científico. Os resultados são úteis para finanças pessoais, monitoramento de saúde, projetos técnicos ou objetivos educacionais. A ferramenta processa seus dados localmente para manter a privacidade. Gratuito, sem cadastro.

What is password entropy and why does it matter?

Password entropy is measured in bits and quantifies the unpredictability of a password. It is calculated as: entropy = length × log₂(charset size). An 8-character lowercase-only password has a charset of 26, yielding 8 × 4.7 = 37.6 bits of entropy. Adding uppercase letters (charset 52) raises it to 45.6 bits; adding digits (charset 62) to 47.6 bits; adding symbols (charset 94) to 52.4 bits. Security experts generally recommend a minimum of 80 bits of entropy for sensitive accounts — achievable with a 14-character password using mixed character types. Every additional character multiplies security exponentially, not linearly.

Brute force vs dictionary attacks: how passwords are actually cracked

Modern GPU-accelerated cracking tools such as Hashcat can test over 100 billion password guesses per second against MD5 hashes — meaning an 8-character password with only lowercase letters can be cracked in under 2 seconds. Dictionary attacks are even faster: they test millions of common passwords, names and phrases first. NIST SP 800-63B (2017) now recommends prioritising length over complexity — a 16-character passphrase like "coffee-mountain-river-27" is far more secure and memorable than "C0ff33!m@" despite being easier to type. Generate strong passwords with our Password Generator, then verify their strength here.