Universal Price Tracker Multi-Site Aggregator

WHAT IT DOES

Universal Price Tracker Multi-Site Aggregator scans the current page for product prices across multiple e-commerce sites (Amazon, eBay, Walmart, Best Buy, etc.) and aggregates them for comparison. It extracts product names, prices, images, and seller information from product pages and search results. The floating panel shows price comparisons from different sites, highlighting the lowest price, price history trends, and price per unit. Add products to a watchlist with price drop alerts, set target prices, and view historical price data. One-click navigation takes you to each product listing, and tracked products can be exported as JSON or CSV. Watchlist data can be imported, and price changes are tracked over time with visual trend indicators and notifications for significant price drops.

WHERE IT RUNS

Works on any e-commerce site, including Amazon, eBay, Walmart, Best Buy, Target, Costco, AliExpress, Newegg, and more. The script intelligently detects product information using common selectors and pattern matching. It works best on major e-commerce platforms but can detect product data on most shopping sites with structured product pages.

HOW TO USE

The panel displays the current product's name, price, site, and SKU when you navigate to a product page. Click "Scan Product Page" to detect and display product information. Use "Add to Watchlist" to track the product for price changes. The watchlist shows all tracked products with their current prices and site icons. Click the link icon to navigate to the product page, or the X to remove it from the watchlist. Price history is automatically tracked, showing recent price points. Export your watchlist as JSON for backup, and import previously exported data. Set a price drop alert threshold to receive notifications when prices drop by a specified percentage.

MECHANISM — MULTI-SITE PRODUCT DETECTION WITH PRICE HISTORY TRACKING

The script uses a layered detection strategy to extract product information across different e-commerce sites. It first identifies the site using domain pattern matching, then applies site-specific selectors for product name, price, images, and SKU. A fallback mechanism scans page content for price patterns and product names when specific selectors fail. Price history is stored locally with daily snapshots, and the price drop detection compares the latest price against the oldest recorded price within the date window. The watchlist stores product data with unique IDs combining name and site to prevent duplicates. All extraction runs client-side with no network calls.

THE PANEL

The floating panel is fully draggable and remembers its position per domain. Click the minimize button to collapse it to a small bubble, or press Escape to hide it. The panel automatically adjusts to different screen sizes and can be resized to show more content. All settings, including watchlist and price history, are saved per domain. The panel integrates smoothly with any page layout using the BGPanel framework, maintaining clean separation from page content.

PLEASE NOTE

This script requires the free BotGentz extension to run. It does not send any data to external servers; all extracted product data, watchlist items, and price history remain entirely local to your browser using GM_setValue. The script never reads password fields, hidden inputs, or file inputs. It stores only product names, prices, URLs, and site information from publicly visible page content. Price tracking accuracy depends on the page structure and may vary between sites. Data persists across browser sessions and is isolated per browser profile.