Multi Keyword Highlighter

WHAT IT DOES This tool lets you highlight multiple keywords on any webpage, each with its own distinct color. Add as many keywords as you need, assign a color to each, and toggle individual keywords on or off without losing the others. The tool finds all matches across the page, wraps them in colored highlights, and optionally scrolls to the first match. Highlights are temporary—they affect only your view and are removed when you clear them, disable a keyword, or close the panel. Perfect for researchers, editors, or anyone scanning pages for multiple terms at once. WHERE IT RUNS Runs on any website—articles, documentation, forums, code repositories, dashboards, or any page with text content. It works across all text nodes, skipping script, style, and noscript tags. No per-site configuration needed; the tool automatically scans the entire page for your keywords. HOW TO USE Install the userscript via BotGentz, then open the panel. Add keywords one by one by typing a word or phrase, selecting a color, and clicking "Add". Each keyword appears in a list with its color swatch, a toggle checkbox, and a delete button. Click "Apply Highlights" to highlight all active keywords on the page. Toggle any keyword on or off individually—the highlights update instantly. Click "Clear All Highlights" to remove all highlights. Customize case sensitivity and auto-scroll behavior in the settings section. The tool saves your keyword list across page reloads, so you don't need to re-enter them every time. TECHNICAL MECHANISM The tool uses a TreeWalker to traverse all text nodes in the document, skipping script, style, and noscript tags, as well as its own highlight marks. For each active keyword, it builds a regular expression (case-sensitive or insensitive based on the setting) and scans every text node for matches. When multiple keywords match the same text, the tool merges overlapping matches to avoid nested highlights, preserving the first keyword's color. Each match is wrapped in a with the assigned background color and a CSS class. The original text node is replaced with a document fragment containing alternating text nodes and highlight spans. When a keyword is toggled off, the tool clears all highlights and re-applies only the still-active keywords. This approach preserves the DOM structure and allows fast incremental updates without reparsing the entire page from scratch. THE PANEL The floating panel is built with BotGentz's BGPanel framework. It is draggable—click and drag the panel header to reposition it anywhere on the screen. The panel remembers its position per site via the settings dropdown. It can be collapsed to a small bubble icon by clicking the minimize button, preserving screen space. The panel can be closed and reopened via the BotGentz toolbar. Press the Escape key to quickly close the panel. The panel automatically adjusts its layout for different screen sizes. PLEASE NOTE Requires the free BotGentz extension. This tool processes text entirely in your browser and does not send any data to external servers. Highlights are temporary and do not modify the underlying page content. Your keyword list and settings are saved locally via GM_setValue and persist across page reloads and browser sessions. Websites change frequently; if the tool stops working on a particular site, the script may need updating. The tool cannot highlight text inside password, hidden, or file input fields.