Alt Text Auditor

WHAT IT DOES

Alt Text Auditor is a browser extension that scans any webpage for all images and checks if they have alt text. It highlights images that are missing alt text (red) or have empty alt attributes (orange), and shows a list of all images with their alt text status: present (green), missing (red), empty (orange), or decorative. The tool helps you identify accessibility issues and ensures that all images on your page have appropriate alt text for screen reader users. You can toggle the feature on or off and choose whether to highlight problematic images. The tool is ideal for web developers, accessibility testers, content creators, and anyone who wants to ensure their images are accessible.

WHERE IT RUNS

Alt Text Auditor 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 image elements. 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 auditor. Toggle "Highlight problematic images" to show a red or orange outline on images with missing or empty alt text. The panel displays a summary count of total images, those with alt text, empty alt, and missing alt. A list shows each image with its source URL, alt text preview, and a status badge. Click the "Scan Page" button to manually rescan for images. The tool automatically rescans when the page content changes. All settings are saved per website.

REAL MECHANISM — WHY THIS WORKS

Most alt text checkers require manual inspection of the page source or external tools that may not show the actual page context. Alt Text Auditor uses a DOM-scanning approach that directly reads image elements from the page. The tool queries the page for all img elements, then checks the alt attribute using getAttribute("alt"). It classifies each image: "present" if alt has a non-empty string, "empty" if alt exists but is empty, and "missing" if the alt attribute is not present at all (null). The tool also highlights problematic images using CSS outlines with color-coded borders: red for missing alt text and orange for empty alt. A list of all images is displayed with status badges, showing the source URL (truncated) and the alt text content. The tool uses a MutationObserver to detect dynamically added images and rescans automatically. This approach ensures accurate, fast, and fully private alt text auditing 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 image 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

Alt Text Auditor 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 checks for the presence of the alt attribute on img elements. Empty alt text (alt="") is considered acceptable for decorative images but is flagged as a potential issue. The tool does not analyze the quality of alt text, only its presence. The highlights are purely visual and do not modify the page content. All settings are stored locally in your browser using GM_setValue. No image data, page content, 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 alt text status at your request.