Structured Data Highlighter

WHAT IT DOES

Structured Data Highlighter is a browser extension that scans any webpage for structured data and highlights the elements containing it with color-coded indicators. It supports three major structured data formats: JSON-LD (purple), Microdata (blue), and RDFa (green). The tool shows a list of all found structured data items with their types and properties, making it easy to understand the page's structured data implementation. You can toggle the feature on or off and choose whether to highlight the data on the page. The tool is ideal for SEO professionals, web developers, content managers, and anyone who wants to verify structured data implementation on web pages.

WHERE IT RUNS

Structured Data Highlighter 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 structured data. 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 highlighter. Toggle "Highlight structured data on page" to show color-coded outlines on elements containing structured data. The panel displays a summary of found structured data items with counts per type (JSON-LD, Microdata, RDFa). A list shows each structured data item with its label and properties. Click the "Scan Page" button to manually rescan. All settings are saved per website.

REAL MECHANISM — WHY THIS WORKS

Most structured data tools require copying code into an external validator or using complex browser extensions. Structured Data Highlighter uses a DOM-scanning approach that reads structured data directly from the page. The tool scans for three formats: JSON-LD (script tags with type="application/ld+json"), Microdata (elements with itemscope attribute), and RDFa (elements with typeof attribute). For JSON-LD, the tool parses the JSON content and extracts properties. For Microdata, it finds elements with itemscope and extracts itemprop properties. For RDFa, it finds elements with typeof and extracts property attributes. Each structured data item is classified by type and assigned a color: purple for JSON-LD, blue for Microdata, and green for RDFa. The tool highlights the containing elements with colored outlines and labels, and displays a list of all found items with their properties. This approach ensures accurate, real-time, and fully private structured data detection 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 structured data 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 highlight toggle—are saved per domain for a seamless experience.

PLEASE NOTE

Structured Data Highlighter 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 scans for JSON-LD, Microdata, and RDFa structured data. It does not validate the correctness of the structured data, only detects its presence. The highlight feature adds visual indicators to elements; these are purely visual and do not modify the page content. All settings are stored locally in your browser using GM_setValue. No page content, structured 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 structured data at your request.