I Built a Privacy-First Currency Converter in 2 Weeks

Source: Dev.to

The Problem 🤦‍♀️

Every currency converter I tried had issues:

• ❌ Forced sign‑ups and email collection
• ❌ Tracked user behavior with cookies
• ❌ Loaded slowly with bloated scripts
• ❌ Bombarded users with ads
• ❌ Required registration for basic features

As someone who travels and shops online internationally, I just wanted a simple tool that respects privacy.

The Solution ✅

I spent 2 weeks building QuickCurrency with these priorities:

• ✅ 30+ world currencies (USD, EUR, GBP, JPY, DOP, and more)
• ✅ Real‑time exchange rates updated hourly
• ✅ Zero registration required – just visit and use
• ✅ 100 % free forever – no premium tiers or paywalls
• ✅ Privacy‑first – no tracking, no cookies, no data collection
• ✅ Lightning‑fast – loads in 2–3 seconds, then instant with caching
• ✅ Works offline after first visit

Tech Stack 💻

• Vanilla HTML/CSS/JS – no frameworks, no bloat
• Exchange Rate API for real‑time data
• LocalStorage caching for instant repeat visits
• Responsive design – works on any device

The entire app loads in 2–3 seconds on first visit. After that? Instant (0.1 seconds) thanks to smart caching.

The Launch 🚀

• Product Hunt – scheduled launch
• Hacker News – Show HN post
• Reddit – r/SideProject community
• Twitter – announcement thread

Results in 24 hours

• 📊 68 active users at peak
• 👥 400+ total visitors
• 🔄 253 currency conversions
• 🔝 Front page of r/SideProject
• ⭐ Listed on Product Hunt

Lessons Learned 📚

1. Privacy messaging resonates – users appreciate the “no sign‑up” approach.
2. Simplicity wins – visitors can start converting immediately, without friction.
3. Multiple platform launches create momentum – cross‑pollination builds credibility.
4. Responsive engagement drives traffic – replying to every comment boosted upvotes and visibility.
5. Community‑driven features work – adding Dominican Peso on request earned loyalty and word‑of‑mouth.

What’s Next 🎯

• Add more currencies (taking requests!)
• Historical rate charts
• Currency conversion alerts
• API access for developers
• Dark mode

Try It 🌍

🔗 QuickCurrency.net

It’s live, it’s free, and it respects your privacy.

Feedback welcome

• What features would make this more useful?
• What other “simple tools” need privacy‑focused alternatives?
• Any bugs or issues you encounter?

Drop a comment below! 👇

Stats

• ⚡ 2–3 sec first load, 0.1 sec after
• 🌍 30+ currencies supported
• 🔒 Zero tracking or data collection
• 💯 100 % free forever

Let’s build tools that respect users! 🚀