Lidar: Measure & Inspect the Web

Precision inspection for the web. Measure spacing, inspect CSS, pick colors, and copy elements for AI. Free, forever.

I got sick of being forced to pay for tools developers shouldn't have to pay for. So I made my own: entirely free and fully open-source. Lidar measures and inspects anything on a web page. Sizes, spacing, distances, colors, computed CSS. No account, no trial, no "Pro" tier, no upsell. Every feature is free, and it stays that way. MEASURE • Hover any element to see its size, padding and margin, drawn right on the page • Click to pin it, then hold ⌥ (Option on Mac) or Alt and hover another element to see the exact distance between them • Spread: lines shoot out from your cursor to the nearest edge in every direction. Switch between Visual (stops at what you see) and Layout (stops at element boxes) • Numbered rulers with your cursor position marked on both • Pixels or rem, your choice INSPECT • Box model, font, line height, colors and computed styles for any element • WCAG contrast grade on every element • Walk the page with the arrow keys: parent, child, siblings • Works inside iframes, web components and page dialogs COPY • Click any value to copy it • Copy CSS: a ready-to-paste rule for the pinned element • Screenshot: a crisp image of just that element • Copy for AI: a markdown brief of the element (selector, layout, styles, text) plus its screenshot, ready to paste into Claude Code, Cursor or any AI coding tool • Built-in color picker BUILT RIGHT • Runs only when you click it. Until then it adds nothing to any page • No "read all your data on all websites" permission • No analytics, no tracking, no network requests, no servers • Dark and light themes • Keyboard first: M measure · D distance · S spread · C color · R rulers · Esc close FREE, FOREVER, AND OPEN Lidar is MIT-licensed and the code is public. Read it, fork it, improve it: https://github.com/vanisov/lidar More is coming, and all of it will be free: flex and grid overlays, a live CSS editor, Tailwind export, design-token export, accessibility and SEO audits, and more.