Calculators — QR code, password, age, currency, tip, BMI.

Why every calculator here is browser-side

A password generator that sends your generated password to a server is a contradiction. A QR code generator that logs every URL you encode defeats the point. An age calculator that needs an internet connection is silly. Pickrack's six calc/generator tools all run entirely in your browser — they have to, because the threat model demands it. (The Currency Converter additionally calls exchangerate-api.com directly from your browser to fetch live mid-market rates; the rates are cached locally for an hour.)

The most security-sensitive of these is the password generator. It uses crypto.getRandomValues from the Web Crypto API, which is a cryptographically secure pseudo-random number generator built into every modern browser. It is not Math.random — that function is fast but predictable, and is not safe for security purposes. Many cheap online password generators get this wrong. You can verify Pickrack's implementation in the source: password-generator/page.tsx.

The six calc tools and what they're good at

• Password Generator — generates strong random passwords using cryptographically secure browser entropy. Configurable length (8-128 characters), character classes (uppercase, lowercase, digits, symbols), and exclusion of ambiguous characters (0/O, 1/l/I) for typing on systems without copy-paste. Always store the result in a password manager (1Password, Bitwarden, Apple Passwords, KeePass).
• QR Code Generator — generates QR codes for URLs, plain text, Wi-Fi credentials (SSID + password + security type), vCards (digital business cards), and email mailto: links. Output as PNG (raster, good for printing on photos) or SVG (vector, infinite resolution, smaller file size). No URL shortener in the middle — the QR encodes whatever you put in it directly.
• Age Calculator — compute age in years/months/days/hours/minutes from any birth date, with leap-year handling. Also shows days until next birthday. Useful for visa applications, legal documents, retirement planning, and the small surprise of finding out you've been alive 14,000+ days.
• Tip Calculator — split a bill, add a tip, optionally round up the total. 7 currencies (USD, EUR, GBP, VND, JPY, AUD, CAD) with currency-appropriate decimal handling. Useful at the restaurant table when you don't want to fumble with a calculator app.
• BMI Calculator — Body Mass Index from height and weight with both metric (cm/kg) and imperial (ft+in/lb) units. Shows the healthy weight range for your specific height, plus a color-coded gauge. Privacy-first — height and weight never leave your browser.
• Currency Converter — convert between 28 major currencies with live mid-market rates from exchangerate-api.com, cached for an hour. Decimal handling per currency (JPY/VND/KRW/IDR show no decimals). Note: real bank transaction rates are typically 2-4% worse than mid-market.

If you have a specific calculator you wish existed — anything that fits the model of "browser-side, instant, no signup" — open an issue at github.com/pickrack/pickrack/issues. Most calculators are under 200 lines of code; many will land within a week of being requested.