Password strength estimator API

Score a password 0-4 (zxcvbn-style) with effective entropy in bits, estimated offline/online crack times, and specific weakness feedback (common-password hits, keyboard/character sequences, repeats, low diversity, missing character classes). Distinct from util-password (generation) and util-password-hash (KDF). Answers 'how strong is this password', 'how long to crack this password', 'why is my password weak', 'what's the entropy of this password'.

Price$0.01per request

MethodPOST

Route/v1/util/password-strength

StatusLive

MIME typeapplication/json

Rate limit60/minute

CacheNo cache

utilpasswordstrengthzxcvbnentropycrack-timesecurityvalidation

API URLhttps://x402.hexl.dev/v1/util/password-strength

Integration docs

Example request

{
  "password": "Tr0ub4dour&3xplosion-Quartz!"
}

Example response

{
  "score": 4,
  "label": "very strong",
  "entropyBits": 167.4,
  "length": 28,
  "charClasses": {
    "lowercase": true,
    "uppercase": true,
    "digits": true,
    "symbols": true
  },
  "poolSize": 95,
  "patterns": {
    "commonPassword": false,
    "sequence": false,
    "repeats": false,
    "lowDiversity": false
  },
  "crackTime": {
    "offlineFastHashing": "1 century",
    "onlineThrottled": "1 century",
    "offlineSeconds": 999999999
  },
  "warnings": [],
  "suggestions": []
}

Input schema

{
  "type": "object",
  "required": [
    "password"
  ],
  "properties": {
    "password": {
      "type": "string",
      "examples": [
        "Tr0ub4dour&3"
      ]
    }
  }
}

Output schema

{
  "type": "object",
  "additionalProperties": true
}