Strong Password Generator - XKCD Passphrases & Entropy Tool

Strong password generator for random passwords or XKCD passphrases. See entropy and crack-time estimatesโ€”secure, client-side only. Generate yours now.

Entropy

********

Entropy: 0.00 bitsCrack time: 0.0 sec

Estimated crack time

CPU
GPU
Cluster

Passwords are generated locally and disappear on refresh.

How to Use

  1. Choose Random or Memorable mode.
  2. Tune length, character sets, word count, or separators.
  3. Click Generate and review entropy + crack-time.
  4. Copy your password, or lock it to prevent regeneration.

Core Features

  • Generate high-entropy random passwords with custom character sets.
  • Create XKCD-style memorable passphrases that are easy to recall.
  • Analyze password entropy and show a clear strength rating.
  • Estimate crack time under different attacker speeds (CPU/GPU/cluster).
  • Exclude ambiguous characters (O/0, l/1) for safer manual entry.
  • Protect privacy with cryptographic, client-side randomness only.

Related Tools

FIRE Calculator 2026 (Inflation Adjusted) | Retirement Gap Simulator

The 2026 FIRE Calculator (Inflation Adjusted). Simulate real purchasing power, analyze retirement savings gaps, and generate a visual wealth roadmap. One-click CSV export for your Excel or Notion finance dashboard. 100% Private, client-side calculation.
Position Size Calculator - Risk-Based Trade Sizing

Calculate trade position size from account balance, risk %, entry, and stop loss. Runs locally in your browser with no uploads, so you can compare risk scenarios before you trade.
Compound Interest Calculator | Free APY & Investment Chart

Calculate compound interest from principal, recurring contributions, APY, and time. Visualize principal, interest, and final balance with a local interactive chart.
Online Loan & Mortgage Calculator - Instant Amortization Schedule

Use this Loan Calculator / Mortgage Calculator to estimate monthly payment, total interest, and an amortization schedule locally. Enter amount, rate, and term to calculate now with instant charts.
Online Investment & ROI Calculator - Compound Interest Visualizer

Use this Investment Calculator / ROI Calculator to estimate starting capital, monthly contributions, annual return, and inflation-adjusted results locally. Calculate projected returns with an instant compound interest chart, ROI, and yearly schedule.
APR to APY Calculator - Convert Nominal & Effective Rates

Use this APR to APY Calculator to convert between APR and APY locally. Enter a rate, choose compounding frequency, and see the effective interest rate, spread, and frequency comparison instantly.
Profit Margin Calculator - Margin vs Markup Converter

Use this Profit Margin Calculator to calculate gross profit, Markup, Margin, and selling price locally. Enter cost and price, or cost and target margin, then calculate your margins instantly.
CPM & CPC Calculator - Ad Spend and CTR Online Tool

Use this CPM Calculator and CPC Calculator to estimate ad spend, impressions, clicks, CPM, CPC, and CTR locally. Enter budget and target costs to plan campaign scenarios instantly.

Calculation Logic

  • Use crypto.getRandomValues for cryptographic randomness.
  • A common entropy approximation is H=Lโ‹…logโก2(N)H = L \cdot \log_2(N).
  • Passphrases gain strength from the size of the word pool and number of words.

FAQ

  • Is it free?
    • Yes.
  • Is my password uploaded or stored?
    • No. Passwords are generated locally and disappear on refresh.
  • Why are passphrases like โ€œcorrect-horse-batteryโ€ better?
    • Theyโ€™re easier to remember while still high-entropy and hard to brute-force.
  • How is entropy calculated? (Technical)
    • A common approximation is H=Lโ‹…logโก2(N)H = L \cdot \log_2(N), where L is length and N is the character set size.
  • Why does length often beat โ€œmore symbolsโ€?
    • Increasing length expands the search space exponentially, usually improving security more than adding complexity alone.