Building a Cross-Browser Extension for Real-Time Lottery Tax Calculation
As an indie developer, I've always been fascinated by how complex underlying math can be simplified through good UI. Recently, when the Powerball jackpot spiked again, I noticed a huge pain point: checking the results and calculating the actual post-tax take-home pay is a fragmented, annoying process across multiple tabs.
So, I decided to build a cross-browser extension (for Chrome, Edge, and Firefox) to solve this. Here is a breakdown of the product design and how the features came together.
(Note: You can check out the live tool and the official dashboard here: PowerballTax.com)
1. The UX Challenge: See the latest draw in one glance
The opening view needed to answer the user's immediate question without them having to dig. I designed the popup to place the five white balls, the red Powerball, the multiplier, and the next-draw countdown in one compact view.
It completely removes the need to keep lottery result tabs open in the background.
2. Navigating State Contexts Without Reloading
One of the trickiest parts of building a lottery calculator is handling state-level rules. I built a draw navigation system that lets users step backward and forward through recent results while keeping the same readable number layout.
3. The Core Logic: Estimating 50-State Taxes
This is where the extension goes from a simple "results viewer" to an actual planning tool. I integrated a calculator that takes the advertised jackpot, cash value, filing status, and residency.
The extension calculates:
The immediate 24% federal withholding.
The remaining federal liability (which often surprises people).
State-specific taxes (covering all 50 states, from 0% in Florida to 10.9% in New York).
Keeping state selection explicit makes comparisons much easier—users can just change the state dropdown, recalculate, and see how the identical jackpot yields completely different net amounts.
4. Cross-Browser Architecture
From day one, the goal was to keep the core workflow the same across Chrome, Edge, and Firefox. The browser packaging differs, but the core calculation engine—powered by my main site, PowerballTax—remains consistent.
The Chrome extension doesn't collect user data. It acts strictly as a focused interface for the core calculation APIs.
Final Thoughts
Building this was a great exercise in packing complex tax logic into a tiny browser viewport. If you want to see how it handles the math, feel free to try the calculator on the site or grab the extension from the Chrome Web Store.
Have you guys built any browser extensions recently? I'd love to hear what build tools (like Webpack or Vite) you are using for cross-browser packaging nowadays!
