Responsive Testing

Multi-Device & Browser Test

Render any site at exact device viewports — including both iPhone Duo screens — and see what each device’s browser is really served. Choose viewports from the sidebar.

Browser Preview

Pick devices in the sidebar, then enter an address.

What Each Browser Is Served

IPBoat requests the page from its own server once per browser, sending that browser’s User-Agent, and compares the replies.

Run a test to see the per-browser report.

The Browser You Are Using Now

Measured in this tab. A page cannot run a different engine, so this describes your browser only.

What This Tool Can and Cannot Tell You

  • The preview is a real viewport, not a picture. Each frame is sized to the device’s CSS pixel dimensions, so the page inside sees that width and runs the matching media queries. Scaling only changes how large the frame looks on your screen.
  • It renders in your engine, not the device’s. A web page cannot run WebKit on Windows or Gecko on a Mac. Layout at a given width is what you are testing here; engine-specific rendering bugs still need the real browser.
  • Many sites refuse to be framed. X-Frame-Options and Content-Security-Policy: frame-ancestors block embedding, and there is no way around that from a browser. When a site is blocked, the server-side report above is the answer — and it names the header responsible.
  • Safari cannot detect a fold. The CSS Viewport Segments API (horizontal-viewport-segments, env(viewport-segment-width)) is Chromium-only, so on iPhone Duo the unfolded screen is just an 890 × 626 viewport to your CSS. Design for the width; use container queries rather than assuming a fold.
  • “Open at this size” needs pop-ups allowed. That window is a pop-up, which is exactly why it works — a pop-up is a top-level window rather than a frame, so the framing headers above do not apply to it. If a blocker is on, nothing will appear and your browser will show a blocked-pop-up icon at the right of the address bar; allow pop-ups for ipboat.com and click again. It also has to be opened by your click, so it cannot be triggered automatically.
  • Touch, hover and input are your computer’s. The frame does not emulate touch events, coarse pointers or on-screen keyboards.