Web Design Ruler — LXB-Studio

Web Design Ruler is a small, honest toolkit for people who build websites. It answers the three questions you ask most while inspecting a page, how big is this, what font is that, and what color is this, without dev tools gymnastics and without phoning home.

Measure. Drag across the page to read width, height, diagonal, and area. Hold Shift to snap to a 10 px grid. Copy any value with one click.

Fonts. Hover any text to see its family, size, weight, style, line height, and color. The detector reports the font that actually rendered, not just the first name in the CSS stack. Save fonts to a history with live previews and copy any of them as CSS.

Colors. Pick from any element, including images and video frames, in HEX, RGB, and HSL. Right click while picking to grab the text color instead of the background. Recent colors are kept automatically, palettes can be saved and shared as JSON, and a built in WCAG checker shows AA and AAA contrast results as you pick. Copy All Colors harvests every color on a page in one right click and copies them as CSS variables.

Quick to reach. Toolbar popup, right click menu, or keyboard: Alt+Shift+R opens the popup, and Alt+Shift+P, F, and M jump straight to each tool. A toolbar badge shows when a tool is armed. Dark mode included, and the Firefox build ships with a Firefox themed starter palette.

Private by design. This add-on collects nothing and transmits nothing. No analytics, no ads, no accounts, and zero network calls in the code, which you can check yourself:

• Privacy policy
• Source code, MIT licensed
• Network call audit

The manifest formally declares that no data is collected, so Firefox shows you that guarantee at install time.

Questions or ideas? Open an issue on GitHub or write to LXBStudioLLC@gmail.com.