Tool Overview

This tool lets you see how a website looks on different device sizes. You enter a web address and pick one or more device presets. The tool loads the site inside frames that look like phones, tablets, laptops, or desktops. You can rotate orientation, zoom the view, draw notes on the previews, take a screenshot of all devices, and run an optional AI check that reports visual issues and a health score.

Many sites break or look wrong on small screens or when the window is resized. Fixing that by hand is slow. You would need to resize the browser, use dev tools, or test on real devices. This tool shows several device sizes at once so you can spot layout and responsive problems quickly. It is for designers, developers, and anyone who cares how a site looks on mobile, tablet, and desktop.

The tool is aimed at people who build or review websites. Beginners can enter a URL and switch devices. More technical users can use annotations, screenshots, and the AI report to document issues and get fix suggestions.

Background & Concept Explanation

Responsive design means a website adapts to the screen size. On a phone the layout may stack vertically. On a desktop it may show multiple columns. Text and images should stay readable and usable at every size. If they do not, users leave or complain. A related operation involves checking your IP address as part of a similar workflow.

Testing responsiveness used to mean resizing the browser window or opening the site on many real devices. That takes time. Another way is to use fixed viewport sizes that match common phones, tablets, and desktops. The tool does that. It loads your URL in iframes sized to match preset devices. You see the real site inside each frame, so you can check if it fits, overflows, or looks broken.

Some sites block being shown inside another site’s page. When that happens the frame will show an error. The tool cannot fix that. You can still use other devices or run the AI analysis if the backend can reach the URL. The optional AI step sends the URL and a device name to a server. The server returns a score and a list of possible visual issues with suggestions. That helps you know what to fix even if you cannot see the site in every frame.

Key Features

• URL input. You enter a full web address. The tool adds https if you omit the protocol. It checks that the URL is valid. After you submit, the tool loads the URL in each selected device frame. This is the main input. Without a valid URL you only see empty device placeholders.
• Device presets. The tool offers preset devices by type: mobile, tablet, laptop, and desktop. Each preset has a name and exact width and height in pixels. You can select more than one device at a time. You add devices by type or by picking from a list. At least one device must stay selected. Frames show the device name and dimensions so you know which size you are viewing.
• Orientation. You can switch between portrait and landscape. In portrait, height is the larger dimension. In landscape, width and height are swapped for the preview. This applies to all selected devices. It helps you test how the site looks when the user rotates the device.
• Zoom. You can zoom the whole view in or out within a set range. This does not change the site’s real viewport. It only changes how big the device frames appear on your screen. Useful when you have many devices or a small monitor.
• Annotations. You can turn on an annotation mode and draw on top of each device preview. Strokes are stored per device. You can clear all annotations. Annotations are included when you take a screenshot. This helps you mark bugs or areas to fix and share them with your team.
• Screenshot. You can capture the current view of all selected devices as one image. The tool sends the URL and device list to a backend. The backend returns images for each device. The tool then composites them with the frames and your annotations and lets you download a single PNG. You must load a URL first. Screenshot may require you to be signed in or may fail if the backend cannot reach the URL.
• AI visual analysis. You can run an optional AI check. The tool sends the URL and the name of one selected device to a backend. The backend returns a health score from zero to 100, a short summary, and a list of anomalies. Each anomaly has a severity, type, message, breakpoint, suggestion, and optionally a CSS fix and element. The report appears in a side panel. If the request fails you may see a fallback message. This feature depends on the backend and network.
• Fullscreen and reset. You can put the tool in fullscreen to use more space. You can reset the view to a single default device and default zoom. On small screens a drawer holds device and action controls so the main area stays clear.
• Shared state. The tool can encode the current URL, selected devices, orientation, AI results, and annotations into a single URL parameter. If you open a link that contains that parameter, the tool restores that state. Useful for sharing a specific test setup or report with others.

Common Use Cases

Quick responsive check. You built or updated a page and want to see it on phone and desktop. You enter the URL, add a mobile and a desktop preset, and look at both frames. You spot overflow or tiny text and fix it before release. For adjacent tasks, looking up IP addresses addresses a complementary step.

Client or team review. You need to show how the site looks on several devices. You select the devices, load the URL, and take a screenshot. You send the PNG so others can see the layout without opening the tool. If you use annotations you can circle issues on the screenshot.

Finding breakpoint issues. You run the AI analysis after loading the URL. The report lists possible issues with severity, type, and suggestion. You use the breakpoint and element info to target CSS or layout changes. You then reload and run the analysis again to see if the score improves.

Documenting bugs. You see something wrong on one device. You turn on annotations, draw on that device’s preview, and take a screenshot. The screenshot includes your marks. You attach it to a ticket or email so developers know exactly where the problem is. When working with related formats, checking page speed can be a useful part of the process.

Sharing a test setup. You have a specific URL, device set, and maybe AI results. You copy the page URL that includes the encoded state. You send the link. When someone opens it, the tool loads the same URL, devices, orientation, and report. No need to re-enter anything.

How to Use This Tool (Step-by-Step)

1. Open the tool. You will see a URL input, a list of device presets, and a workspace with one or more device frames.
2. Enter the URL. Type the full address of the site you want to test, for example https://example.com or example.com. The tool will add https if you leave out the protocol. Click submit or press the button to load the URL.
3. Wait for the frames to load. Each selected device will show the site in an iframe. A loading state appears until the frame finishes. If a site blocks embedding you will see an error in that frame. Other devices may still work.
4. Add or remove devices. Use the device menu or toolbar to add mobile, tablet, laptop, or desktop presets. You can select several at once. Toggle a device off to remove it from the view. You must keep at least one device selected.
5. Change orientation if needed. Click the rotate control to switch between portrait and landscape. The dimensions of each frame update. Check how the site looks in both orientations.
6. Adjust zoom. Use the zoom controls to make the device frames larger or smaller on your screen. This does not change the real viewport size inside each frame.
7. Annotate if you want. Turn on annotation mode. Draw on a device preview with the mouse or touch. Your strokes are saved for that device. Turn off annotation mode when done. Use clear annotations to remove all strokes.
8. Take a screenshot if you need it. Click the screenshot button. The tool will request images from the backend and then build one picture of all devices and annotations. A PNG will download. This can take a few seconds and may require you to be signed in.
9. Run the AI analysis if you want. Click the AI button. The tool sends the URL and a device name to the backend. Wait for the result. A side panel will show the health score, summary, and list of issues with suggestions and optional CSS fixes. Close the panel when done. You can run it again after changing the URL or devices.
10. Use fullscreen or reset as needed. Use fullscreen to get more space. Use reset to go back to one default device and default zoom. On mobile use the drawer to access device and action controls.

Reference: Device Categories

Each category has one or more named presets with fixed width and height. The tool shows the exact dimensions next to the device name. Orientation swap applies to all presets.

Tips, Limitations & Best Practices

Use a valid public URL. The tool only accepts http and https addresses. If the site requires login or blocks iframes you will see a failed-to-load state in the frame. The AI analysis may still run if the backend can fetch the URL. In some workflows, pinging hosts is a relevant follow-up operation.

Select only the devices you need. More devices mean more loading and a larger screenshot. Start with one mobile and one desktop preset, then add others if you need to check specific breakpoints.

Annotations are per device and are lost when you clear them or when you change the URL. If you want to keep your marks, take a screenshot before changing the URL or clearing annotations.

Screenshot depends on a backend service. It can fail due to network, auth, or because the backend cannot render the URL. If you get an error, check that you are signed in if required and that the URL is reachable. Try again later if the service is busy. For related processing needs, testing cron schedules handles a complementary task.

The AI report is generated by a remote service. It can return a fallback message if the request fails. The score and suggestions are guidance, not a guarantee. Use them to find possible issues and then verify on real devices or in a browser.

Some sites block being embedded in iframes for security. When that happens the frame shows an error. You cannot fix that from this tool. Use the AI analysis or test the URL in a normal browser at different window sizes instead.

Shared links contain encoded state. Long state can make the URL long. Some messengers or email clients may truncate it. If the link does not restore state, try shortening the selection (fewer devices, no annotations) or share the URL and steps instead.