The free pixel-perfect overlay for Chrome
Sniff out every
stray pixel.
Mockpup is a free pixel-perfect overlay extension for Chrome. It lays your design mockup (a PNG, a JPG or a Figma frame) over the page you're building, so the button sitting 5px low and the card that grew 18px wider show up at a glance.
It's free. No ads, no account, and it doesn't track you.
Not on the Chrome Web Store yet. Until it is, that button just wiggles this line.
Try it: drag the headline, the “Shop the beans” button or the Colombia card. Let go near the dashed outline and it snaps onto the mockup. Arrow keys nudge 1px, Shift 10px.
Your turn: design vs build.
Here's a design and the page a developer built from it. Five things don't match. Click them in the build before the clock runs out, or hit “Show me” and let the pup find all five in one click.
Keyboard: Tab through the parts of the build, Enter to pick one.
Click anything in the build that doesn't match the design.
Compare mode
Mockpup found them in 1 click.
You found 0 of 5.
Identical pixels cancel out to black. Only the mismatches glow.
Free, and not on the Chrome Web Store just yet.
The toolkit: overlay, compare, wipe, loupe.
It docks beside the page you're building. Scroll through its five views.
Free, for real.
No ads, no sign-up, no tracking, no cookies.
Other overlay tools capped their free layers, went behind a paywall and started showing ads. Mockpup gives you unlimited layers and folders, no account to create, and your mockups never leave your browser.
Add to ChromeChrome first, Firefox after that. Neither store listing is live yet.