Responsive Design Tester

Multi-device viewport testing made simple

Website URL

Device Presets

Mobile Devices

iPhone 15 Pro

393 × 852

iPhone 15

393 × 852

iPhone SE

375 × 667

Samsung Galaxy S24

412 × 915

Google Pixel 8

412 × 915

OnePlus 11

412 × 915

Tablet Devices

iPad Pro 12.9"

1024 × 1366

iPad Air

820 × 1180

iPad Mini

744 × 1133

Samsung Galaxy Tab S9

1024 × 1366

Surface Pro 9

912 × 1368

Desktop Devices

MacBook Pro 16"

1728 × 1117

MacBook Air 13"

1440 × 900

Dell XPS 15

1920 × 1080

Surface Laptop 5

1536 × 1024

Ultra-wide (1440p)

2560 × 1440

4K Display

3840 × 2160

Custom Viewport

Responsive Design Tester

Multi-device viewport testing made simple

Features

  • Multi-device viewport testing
  • Real-time responsive preview
  • Device preset library with 20+ devices
  • Custom viewport controls
  • Screenshot capture and export
  • Responsive design analysis
  • Performance metrics
  • Accessibility testing
  • Mobile-friendliness scoring
  • Layout shift detection

How to use

  1. Enter the website URL you want to test
  2. Select device presets from mobile, tablet, or desktop categories
  3. Create custom viewports with specific dimensions if needed
  4. Choose testing mode (Live Preview, Screenshot, or Analysis)
  5. Click 'Test Responsive Design' to start testing
  6. Review results, metrics, and recommendations
  7. Export screenshots or analysis reports

Tips & Best Practices

  • Preview changes in real-time as you adjust the settings.
  • Copy the generated code directly into your CSS stylesheet.
  • Test your designs in both light and dark mode for accessibility.
  • Use the browser developer tools alongside this tool for live testing.
  • Save your favorite configurations for quick access later.

FAQ

What devices can I test with?

Test across 20+ device presets including iPhone 15 Pro, iPad Pro, Samsung Galaxy S24, MacBook Pro, and more. You can also create custom viewports with any dimensions.

Can I test local HTML files?

Yes, you can upload local HTML files or test localhost URLs for development testing. The tool supports both local and remote websites.

How accurate are the device simulations?

Our tool uses real device dimensions, pixel densities, and user agents for accurate responsive testing. Each preset is based on actual device specifications.

Can I export test results?

Yes, export screenshots, analysis reports, and responsive design recommendations in multiple formats including PNG, PDF, and detailed JSON reports.

Does the tool work with JavaScript-heavy sites?

Yes, the live preview mode supports full JavaScript execution and interactive testing. You can test forms, animations, and dynamic content.

What testing modes are available?

Three modes: Live Preview for interactive testing, Screenshot for visual comparison, and Analysis for detailed responsive design auditing with metrics and recommendations.

How do I create custom viewports?

Use the Custom Viewport section to set specific width, height, and orientation. Perfect for testing unique screen sizes or specific breakpoints.

What metrics does the analysis provide?

The analysis includes load time, accessibility scores, mobile-friendliness, layout shifts, and detailed issue reports with actionable recommendations. This is designed to handle both simple and complex use cases efficiently, giving professional developers a reliable everyday tool.