Responsive Website Testing

Try Free Online Responsive Testing Now!

Enter your website URL below and you can instantly see how it looks on different screen sizes and devices.

What is responsive testing?

Responsive testing is a form of cross-browser testing that allows you to check how a website works on different screen sizes, resolutions, and aspect ratios. This includes desktops (like Windows 11 and macOS), laptops (with regular and 4k resolutions), tablets (iPads), and phones (iPhones and Androids). A responsive site should resize cleanly, keep text readable, and avoid broken layouts on any screen. With Browserling, responsive testing runs in real browsers on real operating systems. You're not guessing how things look but you're seeing exactly what users see.

How does Browserling's responsive testing work?

Browserling runs browsers inside online virtual machines and streams them to your screen. Each session is isolated and starts clean. You can pick a device, choose a screen size, and load your site. You can also resize the browser window, switch resolutions, rotate screens, and reload the page as needed. Developer tools are fully enabled (press F12 to access), so you can inspect CSS, debug media queries, and test layout logic live. When you close the session, everything resets.

Why does responsive testing matter?

Users don't all use the same screen. Some are on wide monitors. Others are on small phones. Many are somewhere in between. If your layout breaks at one size, users notice fast.

Responsive testing helps you:

  • Catch layout bugs before users do. Spot broken layouts, overflow issues, and elements that jump or overlap at certain screen sizes.
  • Fix CSS media query issues. Check that breakpoints trigger at the right widths and styles apply as expected.
  • Test mobile and tablet views without devices. Preview real mobile-sized screens without setting up phones or emulators.
  • Validate UI scaling and spacing. Make sure text, images, and components scale evenly as the viewport changes.
  • Make sure buttons, menus, and forms still work. Check if interactive elements stay usable, clickable, and readable on small screens.
  • Verify flexbox and grid layouts across breakpoints. Catch alignment issues, wrapping problems, and collapsed columns early.
  • Check viewport and zoom behavior. Make sure meta viewport settings don't cause unwanted scaling or horizontal scrolling.
  • Test sticky headers and fixed elements. Confirm fixed navs, footers, and overlays don't cover content on smaller screens.
  • Review font rendering and line breaks. Catch text clipping, bad line wraps, and inconsistent font sizing across screen widths.
  • Confirm image and media responsiveness. Ensure images, videos, and embeds resize correctly without stretching or cropping.

Responsive Testing Demo

To try responsive testing, enter your website URL below and we'll open it in a live browser with adjustable screen sizes:

The free demo lets you test Windows 10 resolutions for a short time. To unlock more browsers, devices, and resolutions (including 4k), you'll need a premium subscription.

Who uses Browserling for responsive testing?

Browserling is used by front-end developers, QA teams, and enterprise engineering teams who need fast, accurate layout testing without setting up devices or virtual labs. It's commonly used during development, bug fixing, and pre-release checks.

Responsive Testing FAQ

Do you support 4k screen resolutions?

Yes. We support 4K screen resolutions, including 3840×2160. This lets you test how your site looks on large, high-DPI displays, catch scaling issues, and verify that layouts, images, and UI elements still look sharp on ultra-high-resolution screens.

Do you support custom screen resolutions?

Yes, you can render your site at exact screen sizes, from small mobile widths to large desktop and 4k displays. This makes it easy to test breakpoints and layout changes. You can also test non-standard screen sizes, like square kiosk displays (for example 800×800, 1080×1080, or 1024×1024), digital signage layouts (such as 1920×540 or 3840×1080), point-of-sale screens, and fixed-resolution internal dashboards where the viewport never changes.

Can I do responsive testing on macOS?

Yes. Browserling supports responsive website testing on real macOS systems using native browsers like Safari, as well as Chrome, Firefox, Edge, Opera, Brave, Vivaldi, and even Tor. You can resize the browser window, test different screen resolutions, and check how layouts, fonts, and UI elements behave on macOS. Try responsive testing on macOS.

Which macOS screen sizes do you support?

We support a wide range of macOS screen resolutions, from smaller laptop-sized displays to large desktop ones. This also includes common external display resolutions. You can test different window sizes and aspect ratios to make sure your layouts, fonts, and UI elements render correctly on macOS screens. Try responsive testing on macOS.

Here's a list of all macOS resolutions that are available:

  • 1920×1440 (4:3 aspect ratio)
  • 1600×1200 (4:3 aspect ratio)
  • 1280×960 (4:3 aspect ratio)
  • 1024×768 (4:3 aspect ratio)
  • 1920×1080 (16:9 aspect ratio)
  • 1600×900 (16:9 aspect ratio)
  • 1366×768 (16:9 aspect ratio)
  • 1280×720 (16:9 aspect ratio)
  • 1920×1200 (16:10 aspect ratio)
  • 1680×1050 (16:10 aspect ratio)
  • 1440×900 (16:10 aspect ratio)
  • 1280×800 (16:10 aspect ratio)
  • 2560×1440 (custom aspect ratio)
  • 2048×1536 (custom aspect ratio)
  • 1280×1024 (custom aspect ratio)
  • 800×600 (custom aspect ratio)

Can I do responsive testing on Windows?

Yes. Browserling supports responsive testing on real Windows systems using the most popular browsers (Chrome, Firefox, Edge, and others). You can test your site at different window sizes and screen resolutions to catch layout, scaling, and interaction issues across common Windows desktop screen sizes. Try responsive testing on Windows 10.

Can I do responsive testing on Android?

Yes. Browserling supports responsive browser testing on Android using real Android browsers. Try responsive testing on Android.

Can I do responsive testing on iPhone?

Yes. You can do responsive testing on iPhone using real iOS browsers. Browserling lets you test your site on actual iPhone screen sizes and iOS versions, so you can see how layouts, text, and touch elements behave on real mobile viewports instead of simulated ones. Try responsive testing on an iPhone.

Which iPhone resolutions do you support?

We support all common iPhone screen resolutions across multiple iOS versions (15, 16, 17, 18, 26). This includes older models with smaller screens and newer iPhones with larger, high-DPI displays. You can test standard portrait and landscape sizes to make sure your layout, text, and touch targets work correctly on real iPhone viewports. Try responsive testing on an iPhone.

Here's a list of all iPhone resolutions that are available:

  • 420×912 (iPhone Air)
  • 402×874 (iPhone 17)
  • 440×956 (iPhone 17 Pro Max)
  • 402×874 (iPhone 17 Pro)
  • 390×844 (iPhone 16e)
  • 430×932 (iPhone 16 Plus)
  • 393×852 (iPhone 16)
  • 440×956 (iPhone 16 Pro Max)
  • 402×874 (iPhone 16 Pro)
  • 430×932 (iPhone 15 Pro Max)
  • 393×852 (iPhone 15 Pro)
  • 430×932 (iPhone 15 Plus)
  • 393×852 (iPhone 15)
  • 430×932 (iPhone 14 Pro Max)
  • 393×852 (iPhone 14 Pro)
  • 428×926 (iPhone 14 Plus)
  • 390×844 (iPhone 14)
  • 375×667 (iPhone SE (3rd gen))
  • 390×844 (iPhone 13)
  • 360×780 (iPhone 13 mini)
  • 428×926 (iPhone 13 Pro Max)
  • 390×844 (iPhone 13 Pro)
  • 428×926 (iPhone 12 Pro Max)
  • 390×844 (iPhone 12 Pro)
  • 390×844 (iPhone 12)
  • 360×780 (iPhone 12 mini)
  • 375×667 (iPhone SE (2nd gen))
  • 414×896 (iPhone 11 Pro Max)
  • 375×812 (iPhone 11 Pro)
  • 414×896 (iPhone 11)
  • 414×896 (iPhone Xʀ)
  • 414×896 (iPhone Xs Max)
  • 375×812 (iPhone Xs)
  • 375×812 (iPhone X)
  • 414×736 (iPhone 8 Plus)
  • 375×667 (iPhone 8)
  • 414×736 (iPhone 7 Plus)
  • 375×667 (iPhone 7)
  • 320×568 (iPhone SE (1st gen))
  • 414×736 (iPhone 6s Plus)
  • 375×667 (iPhone 6s)

Can I do responsive testing on iPad?

Yes. You can do responsive testing on iPad using real iOS browsers. Browserling lets you test your site on real iPad screen sizes across multiple iOS versions (15, 16, 17, 18, 26), in both portrait and landscape modes. This helps you check layouts, spacing, and navigation on tablet-sized screens. Try responsive testing on an iPad (once the page loads, select iPad model from the menu).

Which iPad resolutions do you support?

We support all common iPad screen resolutions across multiple iPad models and iOS versions (versions 15, 16, 17, 18, 26). This includes standard, retina, and larger Pro displays in both portrait and landscape modes. You can test how your layouts, grids, and navigation adapt to tablet-sized viewports. Try responsive testing on an iPad (once the page loads, select iPad model from the menu).

Here's a list of all iPad (and iPod) resolutions that are available:

  • 1032×1376 (iPad Pro 13″ (M5))
  • 834×1210 (iPad Pro 11″ (M5))
  • 1032×1376 (iPad Pro 13″ (M4))
  • 834×1210 (iPad Pro 11″ (M4))
  • 744×1133 (iPad mini (A17 Pro))
  • 820×1180 (iPad (A16))
  • 1024×1366 (iPad Air 13″ (M3))
  • 820×1180 (iPad Air 11″ (M3))
  • 1024×1366 (iPad Air 13″ (M2))
  • 820×1180 (iPad Air 11″ (M2))
  • 1024×1366 (iPad Pro 12.9″ (6th gen))
  • 834×1194 (iPad Pro 11″ (4th gen, cell))
  • 834×1194 (iPad Pro 11″ (4th gen))
  • 744×1133 (iPad mini (6th gen))
  • 820×1180 (iPad (10th gen))
  • 820×1180 (iPad Air (5th gen))
  • 1024×1366 (iPad Pro 12.9″ (5th gen))
  • 834×1194 (iPad Pro 11″ (3rd gen))
  • 820×1180 (iPad Air (4th gen))
  • 810×1080 (iPad (9th gen))
  • 810×1080 (iPad (8th gen))
  • 834×1112 (iPad Air (3rd gen))
  • 768×1024 (iPad mini (5th gen))
  • 1024×1366 (iPad Pro 12.9″ (4th gen))
  • 834×1194 (iPad Pro 11″ (2nd gen))
  • 1024×1366 (iPad Pro 12.9″ (3rd gen))
  • 834×1194 (iPad Pro 11″ (1st gen))
  • 810×1080 (iPad (7th gen))
  • 768×1024 (iPad (6th gen))
  • 834×1112 (iPad Pro 10.5″)
  • 1024×1366 (iPad Pro 12.9″ (2nd gen))
  • 768×1024 (iPad (5th gen))
  • 1024×1366 (iPad Pro 12.9″ (1st gen))
  • 768×1024 (iPad Pro 9.7″)
  • 768×1024 (iPad Air 2)
  • 768×1024 (iPad mini 4)
  • 320×568 (iPod touch (7th gen))

Do I need to install anything to run responsive tests?

No. Everything runs in your browser. The browsers and devices run on Browserling's servers, and you just connect to them. No downloads, plugins, or setup needed.

Can I resize the browser window manually?

Yes. You can resize the browser window freely during a session. This is useful for testing fluid layouts and checking how your site reacts between breakpoints.

Can I rotate screens for mobile and tablet testing?

Yes. You can switch between portrait and landscape modes on phones and tablets to test rotation behavior and orientation-based layouts.

Can I test orientation-specific layouts?

Yes. You can rotate mobile and tablet screens to test portrait and landscape layouts and catch issues tied to orientation changes.

Can I test responsive images and srcset?

Yes. You can inspect which image sizes load at different resolutions and confirm that responsive images switch correctly.

Can I test responsive typography?

Yes. You can check font scaling, line height, wrapping, and text overflow across screen sizes and browsers.

Can I debug responsive issues in JavaScript?

Yes. With DevTools enabled (press F12), you can inspect resize events, viewport calculations, and JS logic tied to screen size changes.

Can I test responsive issues on staging or local sites?

Yes. Browserling supports secure local tunneling, which lets you test local builds, staging servers, or internal sites that aren't public yet.

Can I use developer tools during responsive testing?

Yes. All browser sessions come with full developer tools enabled. You can inspect elements, debug CSS and JavaScript, check media queries, and view network requests.

Can I test flexbox and grid edge cases?

Yes. Responsive testing is useful for finding flex and grid issues like wrapping problems, uneven columns, and alignment bugs that only show up at certain widths.

Can I test responsive navigation menus?

Yes. You can test hamburger menus, dropdowns, sticky nav bars, and mobile headers to make sure they open, close, and stay usable on smaller screens.

Can I test responsive tables and data-heavy pages?

Yes. This is especially helpful for dashboards and admin panels. You can see how tables scroll, wrap, or collapse on tablets and phones.

Can I test responsive layouts in older browsers?

Yes. You can test responsive behavior in older browser versions to see how layouts behave when newer CSS features aren't fully supported. Try responsive testing on Internet Explorer 6.

Can I take screenshots at specific resolutions?

Yes. You can capture screenshots at exact screen sizes. This is helpful for design reviews, bug reports, or sharing layout issues with your team.

Is responsive testing useful for web apps, not just websites?

Yes. Responsive testing works for dashboards, admin panels, SaaS apps, and internal tools. It's especially useful for apps with complex layouts or data tables.

Will my testing session data be saved?

No. Each session starts clean and resets when you close it. Cookies, storage, and files are wiped automatically on session end.

Does Live API work with custom screen resolutions?

Yes. Our Live API lets you change the screen resolution of the embedded browser. You can specify the exact width and height values of the browser and the OS will attempt to resize the display accordingly, which is useful for testing responsive layouts at specific breakpoints via automation. Note that resolution changes may be ignored if the platform or display mode doesn't support them.

What is Browserling?

Browserling is an online responsive and cross-browser testing platform that lets you run real web browsers on real operating systems in the cloud. Web developers and QA teams use it to test websites across different browsers, devices, screen sizes, and operating systems without setting up local environments or devices. It's commonly used for responsive testing, cross-browser testing, debugging layout issues, and checking how sites behave across real user screen and device setups.

Any other questions about responsive testing?

Please contact us at hello@browserling.com or use our contact form. Thank you!