🪙 Vekslák

Bitcoin exchange calculator for ethical exchangers

Fast, simple, and accurate BTC/fiat calculator with real-time rates and multi-currency support.

🌐 Live Site: https://vekslak.dvadsatjeden.org

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✨ Features

• 💱 Real-time rates - Live BTC prices from Binance API
• 🌍 Multi-currency - EUR, USD, CZK, PLN, HUF, PYG support
• 🔄 Buy/Sell modes - Calculate both directions with custom fees
• ⚡ BTC/SATS toggle - Switch between Bitcoin and Satoshi units
• 🔢 Custom number format - International (1,000.50) or European (1 000,50)
• 🌐 Multi-language - English, Slovak, Czech, Polish, Hungarian, German, Spanish
• 📸 Screenshot sharing - Export calculations as images
• 💾 LocalStorage - Remembers your preferences

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🚀 Quick Start

Visit https://vekslak.dvadsatjeden.org

Prerequisites

Node.js 18+ 
npm or yarn

Installation

# Clone repository
git clone https://github.com/yourusername/vekslak.git
cd vekslak

# Install dependencies
npm install

# Start development server
npm run dev

Open http://localhost:5173

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📱 Usage

Basic Calculation

1. Select mode: BUY or SELL
2. Enter amount: EUR/USD/CZK/PLN/HUF/PYG or BTC
3. Set fee: Your commission percentage
4. View result: Instant calculation with BTC amount

Settings

• Currency: Choose base currency (EUR, USD, CZK, PLN, HUF, PYG)
• Language: Select UI language
• Number Format: International or European number formatting

Copy & Share

• Click copy icon to copy BTC amount to clipboard
• Click screenshot to capture and share calculation

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🛠️ Tech Stack

• React 18.3 - UI framework
• Vite 5.4 - Build tool
• Tailwind CSS 3.4 - Styling
• Lucide React - Icons
• html2canvas - Screenshot functionality

APIs

• Binance API - Real-time BTC/USD prices
• ExchangeRate API - Currency conversion rates

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🎨 Features in Detail

Real-time Exchange Rates

// Fetches live BTC price in multiple currencies
- BTC/USD from Binance
- Auto-converts to EUR, USD, CZK, PLN, HUF, PYG
- Updates on demand

Smart Number Formatting

International: 95,842 € (comma thousands, dot decimal)
European:      95 842 € (space thousands, comma decimal)

BUY Mode

Client pays:    500 EUR
Fee:           2%
─────────────────────
Rate with fee: 97,758.84 €
Send to client: 0.00671611 BTC
Your fee:      9.80 €

SELL Mode

Client sells:   0.01 BTC
Fee:           2%
─────────────────────
Rate with fee: 93,825.16 €
Client receives: 938.25 €
Your fee:      19.13 €

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🌐 Supported Languages

• 🇬🇧 English
• 🇸🇰 Slovenčina
• 🇨🇿 Čeština
• 🇵🇱 Polski
• 🇭🇺 Magyar
• 🇩🇪 Deutsch
• 🇪🇸 Español

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💾 LocalStorage Keys

btc-currency        // "EUR" | "USD" | "CZK" | "PLN" | "HUF" | "PYG"
btc-language        // "en" | "sk" | "cs" | "pl" | "hu" | "de" | "es"
btc-number-format   // "international" | "european"

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🔒 Privacy

• No data collection - Everything runs client-side
• No tracking - No analytics or cookies
• No backend - Pure frontend application
• LocalStorage only - Settings saved locally

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📦 Build & Deploy

Build

npm run build
# Output: dist/

Deploy

Vercel:

vercel

Netlify:

netlify deploy --prod

GitHub Pages:

npm run build
# Upload dist/ folder

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🤝 Contributing

Contributions welcome! Please:

1. Fork the repository
2. Create feature branch (git checkout -b feature/amazing)
3. Commit changes (git commit -m 'Add amazing feature')
4. Push to branch (git push origin feature/amazing)
5. Open Pull Request

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📝 License

MIT License

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👤 Author

SiriusBig

• GitHub: @webiumsk
• Website: webium.sk

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🙏 Acknowledgments

• Binance API for real-time BTC prices
• ExchangeRate API for currency conversion
• Dvadsatjeden Bitcoin community for inspiration
• All ethical exchangers using this tool

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⭐ Support

If you find this project useful, please consider:

• ⭐ Starring the repository
• 🐛 Reporting bugs
• 💡 Suggesting new features
• 🔀 Contributing code
• ⚡ Donating to sirius@dvadsatjeden.org

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📄 Changelog

v1.0.6 (Current)

• Added Dark Mode theme toggle
• Added Spanish and German translations
• Added USD and PYG currency options
• SettingsModal redesign — language is now a select dropdown
• Improved BTC price timestamp formatting (European 24h format)
• Created reusable UI components: CalculationPreview, CopyToast, CurrentPriceCard...
• Refactored BTC buying/selling logic into a standalone calculateTrade() function
• Added complete test suite for BUY / SELL modes (BTC input + FIAT input)

v1.0.5

• Made the app installable - Added manifest.json

v1.0.4

• SELL FIAT/BTC Toggle: Users can now input either BTC amount or desired fiat amount in SELL mode
• Two SELL calculation modes:
• Dynamic <html lang=""> attribute based on selected language
• Social media meta tags (Open Graph, Twitter Card)
• Auto-clear amount field when switching between modes

v1.0.3

• 🌐 Added ES language
• ✨ updated readme

v1.0.2

• ✨ Added custom number format selection
• ✨ Added BTC/SATS toggle
• ✨ Added screenshot functionality
• 🌐 Added 5 language support
• 💰 Added 4 currency support
• 🎨 Improved UI/UX
• 💾 Added LocalStorage persistence

v1.0.1

• Added multi-currency support
• Added language selection
• Improved mobile responsiveness

v1.0.0

• Initial release
• Basic BTC calculator
• EUR support only

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Made with ❤️ for ethical exchangers and ₿

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