Password Strength Checker
Estimate entropy and spot weak patterns — never sent anywhere.
Runs in your browser: data never leaves your device. Free, no sign-up. Also known as: password check, entropy, strength meter.
How to use Password Strength Checker
- Paste your input, open a file, or press Sample to see an example.
- Pick a mode or adjust the options; results update instantly.
- Use Copy or Download to take the result with you.
Frequently asked questions
- What does the Password Strength Checker do?
- Estimate entropy and spot weak patterns — never sent anywhere.
- Is the Password Strength Checker free?
- Yes. It is completely free, with no sign-up, no watermark and no usage limits.
- Is my data safe?
- Yes. This tool runs entirely in your web browser. Your text and files are never uploaded to a server, stored or logged.
- Does it work on mobile?
- Yes. It works in any modern browser on Windows, macOS, Linux, Android and iOS, with nothing to install.
- What other security & crypto tools are there?
- Runeforge has 11 security & crypto tools in Cipher Vault, plus 94 more tools across other categories.
More from Cipher Vault
- Hash Generator
MD5, SHA-1, SHA-256, SHA-384 and SHA-512 of any text.
- File Checksum
Hash files locally and verify downloads against a known checksum.
- HMAC Generator
Compute HMAC-SHA256/384/512 signatures in hex or Base64.
- AES-GCM Encrypt / Decrypt
Password-based AES-256-GCM encryption with PBKDF2 key derivation.
- RSA Key Pair Generator
Generate 2048–4096-bit RSA key pairs as PEM.
- RSA Encrypt / Decrypt
Encrypt with a public key and decrypt with a private key (RSA-OAEP).