See the CSS behind
every layout.

A free, privacy-first Chrome extension that overlays the exact margin, padding, gap and dimensions of any element on any webpage — then lets you copy the CSS out.

Coming soon to the Chrome Web StorePrivacy policy

SpaceLens inspecting margin, padding and gap on a design-system webpage

What it does

Everything you need, nothing you don't.

SpaceLens is built to answer one question fast: what CSS made this layout look like this?

Click to inspect

Click any element on any page to see its margin, padding, gap and dimensions overlaid directly on the layout.

Shift+Click to measure

Measure the distance between any two points on the page — no more eyeballing spacing against a ruler.

Live CSS editing

Nudge spacing values and see the layout update instantly, right on the real page — a fixed property allowlist keeps it safe.

Copy CSS in one click

Found the value you needed? Copy the selector and declaration straight to your clipboard, ready to paste into your stylesheet.

Two permissions, period

SpaceLens asks for activeTab and scripting — nothing else. No host permissions, no background access.

Zero data collected

No analytics, no telemetry, no accounts, no network requests. Everything runs locally in your browser.

Built to be trusted

Privacy-first isn’t a tagline here.

SpaceLens is Manifest V3, requests only activeTab and scripting, and ships with a content-security policy that blocks network connections outright. There’s no account, no analytics SDK, and no remote code — every line that runs shipped inside the extension package.

Read the full privacy policy →