r12: grid overlay & layout inspector icon

r12: grid overlay & layout inspector

by r12 · r12.io · Developer Tools
FeaturedEstablished publisherManifest V3 Free
View in Chrome Web Store Data as of 16 Oct 2026

Inspect spacing, margins, alignment, and responsive layouts on any website or design tool.

Users
87
+12 in 30 days
Rating
0.0 / 5
unchanged in 30 days
Ratings
0
0 in 30 days
Store rank
#89K
#74K among extensions
Version
0.2.4
updated 25 Jan 2026

Users

monthly, 11 months
04487Nov 2025May 2026Oct 2026
Latest, 16 Oct 2026: 87 usersMove the mouse over the chart for any month

Ratings count

monthly, 11 months
001Nov 2025May 2026Oct 2026
Latest, 16 Oct 2026: 0 ratingsMove the mouse over the chart for any month

The Chrome Web Store rounds user counts down to the leading digit, so the user line moves in steps. The ratings count is exact and is the better signal of real adoption.

About r12: grid overlay & layout inspector

▔▔▔▔▔▔▔▔▔▔▔▔▔▔ r12 is a precision grid overlay for anyone who values structure — from web designers and developers to creatives and professionals. Activate it with a single click to visualize 12-column, modular, baseline or rule-of-thirds systems directly on websites, documents, design tools or even your resume. Built around clarity, order, and usability. ▔▔▔▔▔▔▔▔▔▔▔▔▔▔ ⊞ GRID OVERLAYS ▪︎ Classic Guides — 12-column, rule-of-thirds, modular, baseline and center lines. ▪︎ Columns & Rows — customizable, responsive grids for any layout. ▪︎ Device Presets — mobile, tablet, laptop, desktop. ▪︎ Gutter Control — adjust inner and outer gutters independently. ⧉ RESPONSIVE MODE ▪︎ Each preset automatically adjusts columns, rows, gutters, and margins. ▪︎ Switch between mobile, tablet, laptop, and desktop layouts. ▪︎ Adjust breakpoint widths for each device. ▪︎ Preview responsive layouts instantly. ⇥ MARGIN CONTROL ⇤ ▪︎ Linked / Unlinked Margins — control spacing uniformly or adjust sides independently. ▪︎ Position grids anywhere — align over resumes, portfolios, design tools, or websites. ▪︎ Outer Gutter Toggle — switch between margin-based or gutter-based edges. ▪︎ Responsive Margins — adapt automatically to device presets. ⌖ PRECISION CONTROLS ▪︎ Drag sliders to quickly set grid values. ▪︎ Use arrow keys for precise adjustments. ▪︎ Contrast Control — adjust color, opacity, and line weight. ▪︎ Live Preview — see changes instantly as you adjust settings. ⛭ PERFORMANCE & PRIVACY ▪︎ Works anywhere — on design tools, web apps, or static pages. ▪︎ State Memory — all controls are synced to browser storage. ▪︎ Lightweight overlays — zero impact on performance. ▪︎ No analytics, cookies, or data collection — ever. ▔▔▔▔▔▔▔▔▔▔▔▔▔▔ ⌘ HOW TO USE ↳ Add r12 to Chrome and pin it to your toolbar. ↳ Click the r12 globe icon. ↳ Adjust columns, gutters, and margins from the popup. ↳ Use Responsive Mode to preview grids across devices. ↳ Review your layouts. ▔▔▔▔▔▔▔▔▔▔▔▔▔▔ ❖ FAQ ▪︎. If grids are not visible, refresh the page or restart the browser. ▪︎. Saves local preferences (grid, margins, color) — no personal data collected. ▪︎ Works on all websites and web-based design tools (e.g., Figma, Canva, Notion). ▪︎ Supports both light and dark modes. ▪︎ Free to use. ▔▔▔▔▔▔▔▔▔▔▔▔▔▔ ⁂ GRID FOUNDATIONS ▪︎ Figma — Layout Grids ⤏ figma.com/best-practices/everything-you-need-to-know-about-layout-grids/ ▪︎ Google — Material Design Layout ⤏ m3.material.io/foundations/layout/understanding-layout ▪︎ Design Lab — History & Theory ⤏ designlab.com/blog/grid-systems-history-ux-ui-layout ▔▔▔▔▔▔▔▔▔▔▔▔▔▔ Questions or feedback? 💌 r12.grids@gmail.com Changelog: r12.io/changelog ▔▔▔▔▔▔▔▔▔▔▔▔▔▔

Growth

WindowUsersChangeRatingsRating
7 days+8+10.1%00.00
30 days+12+16.0%00.00
6 months+57+190.0%00.00

Chrome Web Store search rankings

Where r12: grid overlay & layout inspector appears when people search the store, with the 30 day change
Search phrasePosition30 days
layout#78+2

Version history

8 versions recorded
0.2.412 Jan 2026
0.2.39 Jan 2026
0.2.24 Jan 2026
0.2.131 Dec 2025
0.2.04 Dec 2025
0.1.221 Nov 2025
0.1.119 Nov 2025
0.1.016 Nov 2025

Details

Category
Developer Tools
First seen
16 Nov 2025
Size
38 KB
Languages
en
Pricing
Free
Privacy policy
r12.io
Support
r12.io
Extension ID
pnbjngfpegnppollmgppkdlfdbgchlon

Permissions and risk

Low riskimpact 1, likelihood 1
Permissions
scriptingactiveTabstorage

Alternatives to r12: grid overlay & layout inspector

Extensions that rank for the same store searches or share the Developer Tools category, ordered by users