Comparison Table Builder

WHAT IT DOES

Comparison Table Builder is a browser extension that detects product listings on any webpage and builds a comparison table showing product name, price, rating, and key attributes. You can select which products to compare by checking them in a list, choose which columns to display (Name, Price, Rating, Attributes), and the table updates in real time. The tool extracts product information automatically from the page, including prices (with currency detection), star ratings (visual and numeric), and product attributes. You can copy the comparison table as CSV or Markdown for use in spreadsheets, documents, or websites. The tool is ideal for shoppers, researchers, marketers, and anyone who wants to compare products side by side.

WHERE IT RUNS

Comparison Table Builder runs on any webpage, overlaying a floating panel that does not interfere with page content. It operates entirely in your browser as a lightweight userscript, scanning the DOM for product containers. It works on any page, whether static or dynamic, with no external dependencies. All settings are stored locally using GM_setValue—no data is ever sent to any server.

HOW TO USE

After installation, open the floating panel by clicking the extension icon. The panel shows the current status (Enabled or Disabled) and a toggle button to enable or disable the builder. Click the "Scan" button to detect product listings on the page. The panel displays a list of products with checkboxes—select the products you want to compare. The comparison table updates automatically showing the selected products. Use the column checkboxes to show or hide Price, Rating, and Attributes columns. Click "CSV" to copy the table as CSV, or "MD" to copy it as Markdown. The tool automatically rescans when the page content changes. All settings are saved per website.

REAL MECHANISM — WHY THIS WORKS

Most comparison tools require copying product information manually or using external websites. Comparison Table Builder uses a DOM-scanning approach that automatically extracts product data from the page. The tool searches for product containers using common CSS selectors (.product, .item, .product-card, .listing-item, etc.) and also finds product links by URL patterns (/product/, /item/, /dp/). For each product, the tool extracts the name from heading elements or the container text, the price using pattern matching with currency detection, the rating from star ratings or numeric rating patterns, and key attributes from class-based elements or key-value text patterns. The tool supports multiple currency symbols ($, €, £, ¥, ₹) and extracts both visual star ratings (★ and ☆) and numeric ratings. The comparison table is rendered as an HTML table with the selected columns, and the export functions format the table as CSV or Markdown. A MutationObserver detects dynamically added products and rescans automatically. This approach ensures accurate, real-time, and fully private product comparison without requiring any external services or network access.

THE PANEL

The floating panel is fully draggable and remembers its position per site, snapping to the edges of the viewport when dragged near them. You can collapse the panel to a small icon to minimize screen distraction and expand it back with a single click. The panel is resizable from the bottom-right corner, giving you more space to view the table and product list. Press the Escape key to close the panel instantly. The panel remains open across page navigation within the same domain, maintaining your current view state. All preferences—panel position, enabled state, and visible columns—are saved per domain for a seamless experience.

PLEASE NOTE

Comparison Table Builder requires the free BotGentz extension to be installed and enabled, as it relies on the cross-extension messaging API provided by BotGentz for DOM access permissions. The tool detects product listings using common patterns and may not detect all products on all websites. The extracted rating may be a combination of star count and numeric rating; results may vary. The CSV and Markdown export formats are basic and may not support complex table structures. All settings are stored locally in your browser using GM_setValue. No page content, product data, or usage information is ever sent to any server. The extension does not read, store, or transmit any personal information. It only scans and displays product data at your request.