Auto Alt-Text Prompt

WHAT IT DOES

This script helps you identify and add alt text to images that are missing descriptions. When you visit any webpage, the script scans all images and highlights those without alt text (missing, empty, or generic values like "image" or "photo") with a colored border and a badge. Click on any highlighted image to open a prompt where you can enter alt text. The alt text is stored locally and displayed as a tooltip when you hover over the image. A checkmark badge appears on images that have been given alt text. The script updates dynamically as new images load, making it useful for content creators, developers, and accessibility testers who want to ensure their pages are accessible.

WHERE IT RUNS

The script runs on all websites (*://*/*), making it truly universal. It works on any page with images—articles, galleries, social media, e-commerce sites, and more. It supports both desktop and mobile views.

HOW TO USE

After installation, the settings panel appears on the left side of the screen with the gear emoji (⚙️). Open the panel to configure the script:

- The "Enable alt-text detection" toggle enables or disables the script.

- Use the color picker to change the indicator color for images without alt text.

- Toggle "Show tooltips on images" to show or hide tooltips.

- Click "Refresh images" to manually re-scan the page for new images.

- Click "Clear stored alt text" to remove all locally stored alt text entries.

On any webpage, images without alt text are highlighted with a colored border and a "⚠️ No alt text" badge. Click the image to enter alt text. The alt text is saved locally and shown as a tooltip.

TECHNICAL SECTION — REAL MECHANISM

The script detects images by scanning the DOM for img elements. It checks each image's alt attribute: if the attribute is missing, empty, or contains generic values like "image," "photo," or "picture," the image is flagged as needing alt text. A colored outline (3px solid with offset) and a badge are applied to the image using style properties (never innerHTML). The image's click event is bound to a prompt function. When the user enters alt text, the script stores it in a JavaScript object keyed by a combination of the image's src, alt, class, and id, and persists it via GM_setValue. The image's alt attribute is updated, the indicator is removed, and a checkmark badge is added. The script uses a WeakSet to track processed images and avoid duplicate work. A MutationObserver watches for DOM changes and processes new images as they load. The filename-based suggestion generates alt text from the image's filename (e.g., "sunset.jpg" becomes "Sunset").

THE PANEL

The settings panel is built with BotGentz's BGPanel component. It is draggable via its header, allowing you to reposition it anywhere on the screen. The panel snaps to the left edge by default but can be moved freely. Click the gear emoji to collapse the panel into a small bubble, and click the bubble to expand it again. The panel remembers its position per page session. Press the Escape key to quickly close or minimize the panel. The panel includes a status flash bar that provides visual feedback when settings are changed or actions are performed. All settings and alt text data save automatically via GM_setValue.

PLEASE NOTE

This script requires the free BotGentz browser extension to run. It does not function as a standalone Chrome extension and does not use chrome.* APIs. The script stores alt text locally in your browser—this data is not synced across devices. The alt text prompt uses the browser's built-in prompt() function, which may not be ideal for all users. The script does not modify the page's HTML permanently—changes are only applied in your local browser. The script never reads or writes password fields, hidden inputs, or file inputs. All DOM operations use safe methods (style properties, textContent, appendChild) and never use innerHTML.