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Sifency

Responsive checker

See your site on every screen, at once.

Paste an address and Adjusi opens it on phone, tablet and desktop frames side by side. Drag them to any size, test your media queries, and share the view as a link.

No sign-up. Or open the workbench and paste an address there.

What you get

Everything a responsive check needs, nothing to install

  • Fifteen device presets

    Phones from the folded Galaxy Z Fold to the iPhone 16 Pro Max, tablets, laptops and 2560 px desktops. Switch each one on or off.

  • Drag to any size

    Pull the edge or corner of a frame, or type a number on its dimension line. Find the exact width where a layout breaks.

  • Media query tester

    Type a query and every frame says Matches or No match. It runs against a blank document of the same size, so it works on any page.

  • Breakpoint frames

    Add a frame at sm, md, lg, xl or 2xl in one tap, or any custom width and height up to 4000 px.

  • Share the exact view

    The address bar always holds the page, devices, sizes, query and zoom. Send the link and your teammate sees what you see.

  • Find the breakpoint

    Type a media query and press Find where it flips. Adjusi sweeps every width and tells you the exact pixel where it starts or stops matching.

  • Scroll together

    Scroll one frame and the others follow, level with it, even when the screens have different heights. Works on your own site and in proxy mode.

  • A report in one click

    Add a note to any frame, then copy a clean Markdown summary or print it. Paste it into a ticket or a pull request.

  • Works on localhost

    Pages load directly in your browser, so a dev server on localhost, logins and cookies behave as they do in a normal tab.

How it works

From address to answer in three steps

  1. 01

    Paste an address

    Any public page, a staging site, or http://localhost:3000.

  2. 02

    Pick your screens

    Start with phone, tablet and laptop, or add all fifteen presets.

  3. 03

    Resize, test, share

    Drag a frame until it breaks, test a media query, then copy the link.

Keep every frame on the same page and scroll together

Browsers hide the address of a framed page, so one click or scroll normally moves only one frame. On your own site, add this line before the closing body tag and all frames follow. It only talks to the Adjusi window that framed the page and does nothing anywhere else.

<script src="https://products.sifency.com/adjusi/adjusi-sync.js" async></script>

Questions

Good to know

Why is my page blank or showing an error?
Some sites forbid being shown inside another page. They send a header (X-Frame-Options or a frame-ancestors rule) that every browser obeys. Banks, social networks and many dashboards do this. Your own site is fine as long as it does not send those headers. Where Adjusi’s server is available, Auto mode switches to its proxy for these sites. Otherwise open the page in a new tab to confirm it loads at all.
Is the page I check sent to your servers?
No. Adjusi loads the page straight from its own server into frames in your browser. Only your layout choices (devices, zoom, last queries) are kept, in your browser's local storage.
Can I test a site running on localhost?
Yes. Type http://localhost:3000 or the port you use. Most browsers allow a localhost page inside an https page. If yours blocks it, open Adjusi from the same machine over http.
How does the media query tester work?
Each frame has a hidden blank document with exactly the frame's width and height. Your query is evaluated there, so the result matches what a real browser of that size would report, whatever the previewed page does.
Can I make every frame follow when I click a link?
On your own site, yes. Add the one-line adjusi-sync.js script below and every frame follows the page you navigate to and scrolls with the others. On other sites a click moves only the frame you click in, because browsers hide a framed page's address.
Does this replace testing on a real phone?
It checks layout: widths, breakpoints and wrapping. It does not reproduce a phone's touch input, browser engine or hardware, so keep a real-device pass for those.

Find the width where your layout breaks

Open the workbench and check your page now.

Open AdjusiRead the guide