Website Responsiveness Checker
Enter a URL, pick a device, see exactly how the page looks — the same preset sizes Chrome's own DevTools responsive mode offers, phones through 4K. Runs entirely in your browser.
Choose a size
Some sites block embedding in a frame as a security measure (their choice, not a bug here) — if the preview stays blank, use "Open in a sized window" instead, which opens the real page at this size in a new browser window.
Common questions.
What the Website Responsiveness Checker is
The Website Responsiveness Checker is a free tool that shows your page at different screen sizes. You enter a URL, pick a device size, and the page loads inside a frame set to that width and height.
It is a quick visual check of how your layout behaves on phones, tablets and desktops.
What the checker does and what you get
You enter a URL and choose from a list of preset sizes or type a custom width and height. The page loads in a frame at that size, scaled down to fit your screen if needed.
- Presets for phones, tablets, laptops and a 4K display
- A custom size and a rotate button to swap width and height
- An "Open in a sized window" button that opens the real page at that size
Some sites block being shown in a frame. The sized window works for those. The tool runs in your browser and shows the page for you to judge. It does not score it.
Why we built the Responsiveness Checker
In reviews we often find pages that look fine on the designer's laptop and break on a phone: text running off the screen, buttons too close together, menus that do not open.
Owners rarely see this because they check on one device. We built a fast way to flip through common sizes, so problems are visible before a customer finds them.
Why use this tool and who it is for
Use it after a redesign, before a launch, or when a campaign sends people to a landing page and you want to see what they will see. It suits owners, marketers, designers and developers who want a fast look without installing anything.
It is a good first check before testing on real devices, or opening browser developer tools.
Why responsive design matters
Many visitors reach your site on a phone. If the page is hard to read or tap, they leave, and the work that brought them there is wasted.
Search engines also review the mobile version of your pages, so a poor mobile layout can hurt how the page is understood. A layout that adapts to each screen helps people read, tap and finish what they came to do.
Why this matters more now
Crawlers, including those behind AI search tools, read the content your pages deliver and are built around the mobile version of a page. Content that is hidden, cut off or hard to reach on a small screen is less likely to be read.
People arriving from an AI answer or a social link usually land on a phone and decide fast. A page that fails there loses that visit.
How brands that get this right win
Brands that win design for the smallest screen first, then expand. They keep text readable without zooming, make buttons large enough to tap, and keep forms short.
They check key pages at several widths after each change, and on real devices. They treat the phone view of a landing page as the main version, not an afterthought, and they fix layout bugs before spending on traffic.
What to do to improve responsiveness
- Add a viewport meta tag so phones use their real width.
- Use flexible layouts and relative units instead of fixed widths.
- Keep body text readable on a phone, and make buttons and links easy to tap.
- Make sure images scale down, and that tables and embeds do not force sideways scrolling.
- Test menus, forms and checkout on real phones and tablets.
- Recheck key pages after every design or plugin change.
How the checker helps and when to go further
The checker helps with steps 3 to 6. Flip between sizes to spot overflow, cramped menus and awkward breaks, then rotate to see landscape. Open a sized window when a site blocks framing.
It shows CSS pixel size only. It does not simulate touch, pixel density or slow networks, and it gives no speed score. For speed, mobile usability and indexing checks, our SEO Audit goes further.
Disclaimer
This tool is for information only. It shows a page at a chosen size in your own browser and does not test touch behavior, pixel density, browser differences or network speed. Real devices can look different from this preview. Some sites cannot be shown in a frame, and that is their setting. The URL you enter is not sent to our servers, and results are a visual guide, not a guarantee.
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