Free Everyday Utility Tools
Generate QR codes and passwords, and convert units - handy free utilities for everyday tasks.
About Utility Tools
Make a scannable QR Code, create a strong password, or switch between metric and imperial with the Unit Converter.
These are the little tools that solve small problems fast - all free, all in your browser, no account needed.
Everything here runs locally
The password generator uses your browser's cryptographic random source and the result never leaves your device — which matters, because a generator running on a server necessarily knows every password it produces. QR codes are generated in the page, and unit conversions are arithmetic. Nothing in this category is uploaded.
Unit conversion has real traps
Several unit names refer to more than one quantity. A US gallon is 3.785 litres and an imperial gallon 4.546 — a 20% difference. A ton is 1,000 kg, 907 kg or 1,016 kg depending on which. An ounce is a weight or one of two different fluid measures, and a calorie is either 4.184 joules or a thousand of those. Area and volume scale as the square and cube of the linear factor, which is the most common error in materials estimating: one square metre is 10.76 square feet, not 3.28.
These are not academic concerns. The Mars Climate Orbiter was lost in 1999 to a mismatch between pound-force seconds and newton-seconds, and an Air Canada aircraft ran out of fuel mid-flight in 1983 after a pounds-to-kilograms conversion error. Both involved competent people and correct arithmetic.
QR codes
Two properties decide whether a code scans reliably: error correction level and data density. Keep the encoded data short, size the code at roughly the scanning distance divided by ten, and always leave a quiet zone of at least four modules around it. Codes printed flush against artwork fail more often for this than for any other reason.
Frequently Asked Questions
Are the QR codes free to download?
Yes. You can generate and download QR codes as images with no watermark or sign-up.
Are generated passwords secure?
Yes. They use your browser's strong random generator and are created locally, never sent to a server.
Which units can I convert?
Length, weight, temperature, and the other measures on the unit converter. A US gallon and an imperial gallon are not the same size, and a ton has more than one definition.
Is a generated password sent anywhere?
No. It is produced by your browser's cryptographic random source and never leaves your device. Server-side generators, by contrast, necessarily know every password they create.
Why do gallons and tons have several values?
The US and imperial systems diverged, and a ton has three definitions differing by up to 12%. Always state which system a figure uses — unit mismatches have caused genuinely expensive accidents.
Why won't my QR code scan?
The usual causes are a missing quiet zone around the code, too little contrast, too much encoded data making the pattern dense, or printing it too small for the intended scanning distance.