Preview Any Website On 24 Device Sizes At Once

Responsive design has been the standard for over a decade, but checking that a site actually works across every screen size is still annoying. You drag your browser window. You open DevTools and switch device emulation modes. You forget the iPad mini exists. You ship, and three days later someone messages you a screenshot of your nav bar overlapping the logo on a 13-inch MacBook.

That's the loop Website Multi-Device Preview is meant to short-circuit. Paste a URL. Get back screenshots of the page rendered on 24 real device viewports — phones, tablets, laptops, desktops, ultrawides, 4K — laid out side by side. Spot the layout bug at a glance.

What it covers

24 viewports, grouped into categories so each row stays visually consistent:

• Phones — iPhone (multiple sizes), Pixel, common Android widths.
• Tablets — iPad mini, iPad, iPad Pro.
• Laptops — 13-inch and 16-inch MacBook widths.
• Desktops — standard 1440px, 1920px, 2560px ultrawide.
• 4K — for the case where your hero text becomes 8 pixels tall.

You can render all 24 at once or pick a subset (only mobiles, only desktops, only the breakpoints you actually care about). The full grid is the right call before launch; a tighter pick is more useful day-to-day.

Where it's genuinely useful

• Pre-launch QA.Last-mile responsive check before pointing a domain at a fresh deploy. Catches hero overflow, nav wrap, and font scaling issues that don't show up at the breakpoints you usually test.
• Client demos.“Here's how it looks on every screen your customers might use” lands harder than “trust me, it's responsive”. Drop the screenshots into a deck.
• Design reviews. Designers and developers can stand at one screen and walk through every viewport without anyone having to switch devices or simulate.
• Before pushing a campaign.Email links, social ad landing pages, paid traffic destinations — a quick render across all viewports catches the “CTA invisible on mobile” problem before you spend ad budget on it.
• Comparing competitors.Render a competitor's site on every device size in one shot. See how they handle navigation collapse, hero stacking, and image sizing across breakpoints.

How it actually works

Unlike Pulsyr's PDF and image tools, this one isn't in-browser — it can't be. Rendering a third-party URL at a controlled viewport requires a real headless browser, so the work happens server-side:

1. You submit a URL.
2. Pulsyr's server spins up Chromium (via Puppeteer) at each requested viewport, navigates to the URL, waits for the page to settle, and captures a full-page screenshot.
3. The image is streamed back to your browser and rendered inside a device frame in the grid.
4. Concurrency is capped — multiple devices render in parallel without blasting the target site or the server.

That means: only public URLs work. Sites behind a login wall, region-locked sites, or sites with strict bot detection may render differently than they do for you when signed in. That's a real limitation, not a bug — it's a side effect of using a headless browser instead of a logged-in session.

Why not just use BrowserStack?

BrowserStack, Sauce Labs, and friends are great for full cross-browser interaction testing — clicking, typing, debugging real device quirks. But for a quick layout sanity check across screen sizes, they're wildly heavyweight: signup, paid plans, slow session boot, screenshot APIs that take minutes.

Website Preview is the “zero-setup, get the screenshots, move on” tier. Free, no signup. If you need the full thing, the heavy tools still exist — this just covers the 80% case faster.

Pairs well with

Two other Pulsyr tools that show up in the same workflows:

• Sheet Tracker — turn the Google Sheet you're tracking your launches in into a live dashboard.
• Image Compress — squeeze the device-frame screenshots before pasting them into a Notion doc or client deck.

Try it

Website Preview is live at pulsyr.in/tools/website-tools/website-preview. Free, no signup, no signup-walled credits or quota. Paste a URL and render.

Got a device you'd like added to the grid (a specific phone, a foldable, a particular ultrawide ratio)? Let us know — the device list is configurable and we add what real users ask for.