Free Screen Resolution Simulator
This free screen resolution simulator shows your own screen size and browser window size, and previews any web page at the width of a phone, tablet, laptop or desktop. Pick a device or type a width, paste a page address and the page loads in a frame at that size. A table of common device sizes works even without JavaScript.
Screen Resolution Simulator
Domain and Server
About this tool
A page that looks right on your laptop can break on a small phone, and the only honest way to know is to look at it at that width. This tool loads your page in a frame at the width you choose, so you can check menus, images and buttons at 360, 390, 768 or 1366 pixels without owning each device. It also reports your own screen and window size, which support teams often ask for.
The numbers are CSS pixels, the units a web page layout uses, not the physical pixels of a screen. A phone with a very sharp display still reports a viewport of about 360 to 430 CSS pixels wide, which is what your design must fit. The table lists typical sizes for popular device classes. Real devices differ, and browser toolbars take some height, so treat the sizes as a close guide rather than an exact measurement.
Many websites forbid being shown inside another page, to protect visitors from click tricks. When a site sends that instruction, this tool detects it, shows no preview and says so, rather than showing a blank box. Your own site can be framed if it does not send X-Frame-Options or a frame-ancestors rule. A framed preview also does not run media queries on the device itself, so confirm important layouts on a real phone before you launch.
Frequently asked questions
Why does the preview say the page cannot be framed?
Many sites, including banks, social networks and large shops, send a header that forbids showing the page inside another page, as a protection against click hijacking. The browser would show a blank box, so the tool tells you instead. Test those sites in your browser developer tools device mode.
What is the difference between screen and viewport size?
The screen size is the full display of your device. The viewport is the part of the browser window that shows the web page, which is smaller because of toolbars and scroll bars. Layouts react to the viewport, so that is the number that matters for responsive design.
Are the device sizes exact?
They are typical CSS pixel sizes for common device classes. Phones and tablets vary by model and software, and browser bars change the height. They are accurate enough to catch layout problems, but always test important pages on a real device before launch.
Does this test my site on a real phone?
No. It narrows the frame to a phone width, so the page applies its mobile layout rules, but it still runs in your current browser. Touch behaviour, fonts, browser bars and performance can differ on a real phone. Use it as a fast first check, not the final test.
Is the address I enter stored?
No. Our server requests the page once to read its framing headers and then forgets it. The preview itself loads straight from the website into your browser. We do not save the address, the page content or your screen size.