How to use Seed / Password Strength
Paste a passphrase or seed-like string you are willing to type into a browser. Read entropy and strength labels. Clear the field when finished.
Formula & methodology
Client-side entropy heuristics over character classes and length. No server upload.
Score passphrase strength without leaving your device
Strong phrases beat short passwords, but never reuse a funded seed as a “test string.” Prefer offline generators for real wallets and hardware devices for production keys.
CryptonicTools scores length and character variety in the browser. Clearing the field when finished is part of the hygiene — treat any hot-page entry as higher risk than an offline check.
Pair with BIP39 validation for mnemonic format checks. Neither tool proves ownership or protects you from phishing sites that look similar.
What strength scores do not guarantee
A high score does not mean the phrase is unique, unused elsewhere, or safe to type into a random website. Dictionary phrases and reused passwords still fail in the real world.
For funded wallets, follow vendor hardware flows and never share seeds in chat, screenshots, or cloud notes. This page is educational hygiene math only.
All CryptonicTools utilities are free, mobile-first, and require no account.