Built for Privacy
Designed for You
We're not here to collect your data. We're here to help you understand your take-home pay with zero compromises on privacy.
Free forever. No premium tiers. No paywalls. Just honest tax calculations built with care.
- 100%Free Forever
- 0Data Stored
- HMRCOfficial Rates
- <300kBBundle Size
What We Stand For
The principles that guide every decision we make
Privacy is Sacred
Every calculation runs in your browser. We never see your salary, tax code, or personal details. This isn't a promise - it's architectural impossibility.
Radical Transparency
Open-source philosophy, honest analytics, and clear documentation. No dark patterns, no hidden fees, no corporate speak. Just honest tax calculations.
Accuracy First
Official HMRC rates updated within 24 hours of changes. Comprehensive testing for Scottish rates, student loans, pensions, and edge cases.
Genuinely Free
No premium tiers, no paywalls, no "upgrade to see more". Every feature is free for everyone, forever. Tax calculations should be accessible to all.
What Makes Us Different
Features you won't find in other tax calculators
£100k Tax Trap Optimizer
Automatically detects when you're in the 60% effective tax rate zone (£100k-£125k) and calculates optimal pension contributions to save thousands.
Salary Comparison
Compare job offers or raises with 3 input modes (%, £ amount, total). See marginal rates and exactly what you keep from every increase.
Adaptive Theming
Light, dark, or system-matched themes. Your calculator, your eyes, your choice. Smooth transitions, zero flash, perfect accessibility.
Built with Modern Technology
Professional tools for a free service
Next.js 15 & React 19
Server Components, React Compiler, async request APIs. Built with the latest tech for maximum performance and developer experience.
TypeScript Strict Mode
100% type coverage with strict mode enabled. Every calculation is type-safe. Runtime errors are nearly impossible with our validation layers.
Modern Development
Biome for linting/formatting (10/10 strictness), Playwright for E2E testing, Sentry for error monitoring. Professional tooling for a free service.
Zod Validation
Every input validated at runtime with comprehensive schemas. Type safety meets runtime safety for bulletproof calculations.
Built by One Person
PayeTax is a solo project built with care by a developer who got tired of complicated, data-hungry tax calculators.
Every line of code, every design decision, every privacy guarantee comes from a single person who believes tax calculations should be private, accurate, and free.
Why build this?
Because understanding your take-home pay shouldn't require sacrificing your privacy or paying subscription fees. Tax calculations are a basic utility that should be accessible, accurate, and respect your data.
No VC funding. No premium tiers. No data harvesting. Just a useful tool built because it needed to exist.
Questions or Feedback?
We're always improving. If you have suggestions, found a bug, or just want to say hi, reach out!