Responsive Screen Tester

What is a Responsive Screen Tester?

Test and preview how your website renders across multiple mobile, tablet, and desktop viewports simultaneously (iPhone, iPad, Android Pixel, Laptop, 4K Desktop).

Why Use This Tool?

Responsive Web Design: Test mobile responsiveness and media query breakpoints across multiple screen sizes side-by-side.
Layout Bug Spotting: Spot horizontal overflow scrollbars and broken navigation menus on mobile screens.
Fast Testing: Preview your local or live website URL instantly without switching physical devices.

How to Use

Enter any website URL (e.g. `https://devdeskapp.com`).
Select target device viewport presets (Mobile, Tablet, Desktop, Custom px).
Inspect live responsive rendering across iframe frames.

Real Working Example

Input:

URL: https://devdeskapp.com | Preset: iPhone 15 (393 x 852 px) & iPad (810 x 1080 px)

Output Result:

[Side-by-Side Responsive Viewport Rendering Frames]

Important Technical Details & Features

Iframe Device Simulation: Renders target web page inside responsive iframe containers.
Preset Resolution Profiles: Pre-configured resolutions for popular Apple, Samsung, and desktop screens.
100% Local Execution: Fast in-browser testing.

Related Editors, Design & Media Tools

Device Information: Inspect screen specs and DPR.
CSS clamp() Calculator: Compute fluid responsive sizes.
CSS Units Converter: Convert PX to REM.

Frequently Asked Questions

Can I test local development URLs like http://localhost:3000?

Yes, local server URLs can be tested if your site allows iframe embedding.

Why do some websites refuse to display in the tester?

Sites that send X-Frame-Options: SAMEORIGIN security headers block external iframe previews.

Is it free?

Yes, 100% free.

Can I rotate screen orientation to landscape?

Yes, toggle portrait and landscape orientation with one click.

What is the main function of Responsive Screen Tester?

Free browser tool to preview websites across multiple device viewports: iPhone, Google Pixel, iPad, and Desktop screens. This tool processes responsive screen data 100% locally inside your web browser.