Precise calculators, generators, and utilities that save time and prevent mistakes. Built for developers, designers, and anyone who needs fast, accurate results.
Instant results, step-by-step breakdowns where it matters.
Percentage Calculator for math and discounts, QR Code Generator for branded codes with logos and custom colors.
All tools recalculate instantly as you type — no submit button. Every result includes the formula and intermediate steps.
Copy values as plain text, download QR codes as high-res PNG or vector SVG, and use the result in your project immediately.
Everything you need to know
Developer tools should be fast, accurate, and transparent. Every calculator on this site shows its work — the formula, the intermediate values, and the final result — so you can verify the logic yourself. No black boxes, no misleading rounding.
Most QR code generators lock basic features (custom colors, logos, high-res downloads, SVG export) behind a subscription. Our generator gives you all of them for free, instantly, with no watermark and no expiration. The output is a static image that encodes the data directly — never a redirect through a paid service.
Three modes cover 99% of daily percentage math: what is X% of Y, what does a discount save, and how much did a value change. Each mode handles edge cases (zero values, negative percentages, tax after discount) correctly.
Everything runs locally. Nothing is logged, nothing is transmitted, nothing is stored. The tools work offline after first load, and remain functional even when your network is down. No ads interrupt the tool itself, no popups, no signup walls.
