Currency Conversion Note Tool

WHAT IT DOES

Currency Conversion Note Tool is a browser extension that automatically scans the current webpage for currency symbols, price elements, and monetary values. It detects currency information by examining class names, IDs, data attributes, and text patterns for currency symbols ($, €, £, ¥) and currency codes (USD, EUR, GBP, JPY). The extension adds a floating "convert" button (💱) next to each detected price element, allowing you to convert displayed amounts to your preferred target currency with a single click. Clicking the button opens a panel where you can select a target currency from a dropdown list. The extension fetches real-time exchange rates using GM_xmlhttpRequest from a free currency API, displays the converted amount, and stores the conversion data locally. You can add notes about conversion fees, date-specific rates, market conditions, or any other relevant details. The extension maintains a complete conversion history per product or URL with original currency, target currency, conversion rates, amounts, timestamps, and notes. The main panel displays all tracked conversions, showing the latest conversion details and entry counts. All data is stored locally in your browser using GM_setValue, ensuring your conversion history persists across page reloads and browser sessions. This helps international shoppers, business travelers, and financial analysts quickly understand prices in their home currency and track conversion trends over time.

WHERE IT RUNS

This extension runs on any webpage that displays prices, currency symbols, or monetary values – including e-commerce websites, online marketplaces, travel booking sites, financial dashboards, price comparison platforms, international retailers, and any page showing product or service prices. The extension intelligently adapts to different page structures and supports a wide range of common pricing display patterns. No manual configuration is required per site; the extension automatically detects price elements using a flexible pattern matching system. This makes it ideal for international shopping, cross-border business, and global financial analysis.

HOW TO USE

Simply install the extension and navigate to any webpage displaying prices. The extension automatically detects price elements and places a small "convert" button (💱) next to each one. Click any of these buttons to open the conversion panel with the original amount and currency pre-filled. Select your target currency from the dropdown menu, then click "Convert" to fetch the real-time exchange rate and see the converted amount displayed. Add a note about conversion fees, market conditions, or any relevant detail, then click "Save & Close" to store the conversion in your history. A floating button (💰) appears in the bottom-right corner of the page – click this to open the main panel. The main panel shows all tracked conversions, sorted by most recent entry, with original amount, target currency, converted amount, entry count, and latest note displayed. Click any conversion card to view detailed history, including all logged entries with timestamps, exchange rates, and notes. Use the settings section to set your default target currency and enable auto-conversion on page load.

ONE TECHNICAL SECTION – WHY IT WORKS

The extension employs a multi-layered detection system that identifies currency amounts with high accuracy. First, it scans the DOM using a comprehensive set of CSS selectors targeting common price-related class patterns, IDs, and data attributes like "price", "amount", "cost", and itemprop="price". Second, it uses a TreeWalker to examine text nodes for currency patterns, capturing prices that may not be wrapped in typical price elements. The currency extraction algorithm uses pattern matching to identify both currency symbols ($, €, £, ¥) and ISO currency codes (USD, EUR, GBP, JPY). The exchange rate retrieval uses GM_xmlhttpRequest to fetch rates from a free currency API, with a built-in caching system that stores rates locally to minimize API calls – each cached rate has a configurable expiry time (default 1 hour). The extension also includes fallback exchange rates for common currency pairs in case the API is unavailable, ensuring basic functionality even without network access. Each tracked conversion is assigned a unique ID based on the page URL, amount, and source currency, ensuring that history stays correctly associated even when pages use different query strings. A MutationObserver detects dynamic content updates and re-scans only when new price elements appear, balancing real-time accuracy with system performance.

THE PANEL – DRAG / PER-SITE POSITION / SNAP / COLLAPSE / RESIZE / ESCAPE

The currency conversion panel includes a draggable title bar, allowing you to position it anywhere on screen for convenient access during international shopping. The extension remembers your preferred position per website, so the panel opens in the same location each time you return to that domain. The panel supports snap-to-edge behavior – when dragged near screen edges, it gently snaps into place for a tidy workspace layout. You can collapse the panel down to just its title bar by clicking the collapse button, keeping it accessible without taking up screen space. The conversion results and history are contained within a scrollable body, ensuring all content remains accessible even on smaller screens. Pressing the Escape key closes the panel instantly, returning you to your shopping or financial analysis workflow.

PLEASE NOTE

This extension requires the free BotGentz extension to be installed and enabled, as it relies on BotGentz's userscript injection and GM_* API shims for cross-browser compatibility. Websites frequently update their HTML structures and class names, which may cause price detection to break temporarily – we actively maintain the matching patterns and release updates regularly. The extension stores all conversion data, exchange rates, timestamps, and notes exclusively in your local browser storage (GM_setValue); no data is ever transmitted to any external server except for fetching exchange rates from the public currency API. Exchange rates may not reflect real-time market rates due to API limitations and caching; always verify critical rates through official financial sources. You are responsible for backing up your conversion data if you switch browsers or clear your storage. The extension does not read, modify, or interfere with any payment processing, checkout functionality, or financial transactions – it operates solely on the static page content and stores only metadata (amounts, currencies, rates, and notes) that you explicitly create. Use this tool responsibly for personal and business currency conversion needs.