Parity Canvas

Parity Canvas lets you view two (or more) web pages side by side and interact with them in perfect sync. Click, scroll, type, or navigate in one panel, and watch the same action mirror instantly across every other panel — no matter what device size each one is emulating. Built for anyone who needs to check how a page behaves across breakpoints without manually repeating every test on each screen, Parity Canvas turns responsive QA, cross-browser comparisons, and design reviews into a single synchronized workflow. Key features: Side-by-side canvases — Load the same URL (or different URLs) into multiple embedded viewports at once Mirrored interactions — Clicks, scrolls, form input, and navigation sync across all panels simultaneously Responsive viewport presets — Instantly compare mobile, tablet, and desktop layouts side by side Custom viewport sizing — Set exact pixel dimensions to match your target devices Independent zoom controls — Inspect fine details in one panel without affecting the others Fast layout switching — Rearrange, resize, or add/remove panels on the fly Whether you're a developer verifying responsive breakpoints, a designer checking layout parity across devices, or a QA tester hunting for inconsistencies, Parity Canvas cuts your testing time by letting you see — and interact with — every version of your page at once.