Free Multi-Screen Testing — No Install

Preview your website on
all devices at once

Load any URL once and instantly see how it renders across mobile, tablet, laptop, and desktop — side by side in a synchronized grid. Spot responsive inconsistencies at a glance.

How it works
4
Simultaneous Panels
20+
Device Presets
Free
Forever
Live
Preview
Trusted by teams at
Core Tool

Multi-Device Preview Grid

Enter any URL and instantly preview it across all your chosen devices — simultaneously

Grid Layout
Active Panels
Actions
Enter a URL above and click "Load All Devices"
The Strategy

Why Use Multi-Device Preview?

Single-device simulators make you switch views one at a time. Multi-Device Preview shows them all at once — dramatically faster responsive testing.

63%

Mobile-First Traffic

Over 63% of all web traffic is now mobile. With Multi-Device Preview you validate your mobile, tablet, and desktop experiences simultaneously — leaving no breakpoint untested.

Instant Comparison

Side-by-side comparison instantly reveals layout inconsistencies — a nav item that breaks at tablet width, a font that's too small on mobile, a grid that misaligns on desktop.

Save Hours of Testing

Instead of opening three separate browser DevTools tabs and manually switching device presets, load once and validate all screen sizes in a single workflow.

Better Client Presentations

Show clients their website rendering across all devices at once in a single screenshot or screen share — a far more compelling deliverable than individual device screenshots.

What's Included

Powerful Features for Every Workflow

Built for frontend developers, UI designers, QA engineers, and agency teams

01

Simultaneous Grid Preview

Load a URL once and see it rendered across all active device panels simultaneously. No switching, no re-loading — true side-by-side comparison at a glance.

02

Flexible Grid Layouts

Switch between 2-up, 3-up, and 4-up grid configurations to match your screen space and testing workflow. Each layout adjusts automatically to the available width.

03

20+ Device Presets Per Panel

Every panel has its own device preset selector — choose from iPhone 15, Samsung Galaxy, iPad Pro, standard desktops, and more. Mix and match any combination in the grid.

04

Toggle Panels On / Off

Enable or disable individual device panels without losing their settings. Focus on just mobile vs desktop, or enable all four for the full responsive picture.

05

Individual Panel Controls

Each panel has its own refresh button and preset selector. Reload a single device after a CSS fix without disturbing the other previews in the grid.

06

Zero Install — 100% Free

Entirely browser-based. No Chrome extensions, no npm packages, no sign-up. Open the tool and start testing in under 5 seconds — completely free, forever.

Simple Process

Up and Running in 3 Seconds

No setup, no learning curve — just paste your URL and see all your devices load

01

Paste Your URL

Type or paste any website URL — including localhost or staging servers — into the bar at the top and hit Load All Devices.

02

Compare All Devices

Your site loads simultaneously across mobile, tablet, laptop, and desktop panels. Scan the grid to instantly identify layout issues, text overflow, or broken components.

03

Fix & Refresh

Update your CSS or HTML, then click Refresh All (or refresh individual panels) to confirm the fix across every device without leaving the tool.

About This Tool

What Is Multi-Device Preview?

Multi-Device Preview is a browser-based tool that renders any website URL simultaneously across multiple device screen sizes in a single grid view. Instead of checking each device individually — opening DevTools, switching emulators, resizing manually — you load your URL once and see it on mobile, tablet, laptop, and desktop panels all at the same time.

This approach is fundamentally different from a single device simulator. When you view all breakpoints simultaneously, your eye catches visual inconsistencies that you'd never notice when checking devices one at a time — a headline that only wraps awkwardly at exactly 768px, a CTA button that shrinks too small on mobile while being perfect on desktop, or a grid that collapses incorrectly at tablet width.

It's equally powerful for client presentations and design reviews: a single grid showing your website across all major form factors is a compelling, professional deliverable.

  • Preview mobile, tablet, laptop, and desktop simultaneously
  • Switch between 2, 3, or 4-panel grid layouts
  • Per-panel device preset selector with 20+ options
  • Toggle individual panels on/off without losing settings
  • Refresh all panels or individual panels independently
  • Works with any live URL, localhost, or staging server
  • 100% free — no sign-up, no download, no time limit

Default Device Panels

PanelResolutionType
Mobile 375 × 812 Mobile
Tablet 768 × 1024 Tablet
Laptop 1280 × 800 Laptop
Desktop 1440 × 900 Desktop
Full HD 1920 × 1080 Desktop

Multi-Device Preview vs Single Simulator

Single simulator — one device at a time. Good for deep inspection of a specific device, checking fonts, interactions, and scroll behavior in detail.

Multi-Device Preview — all devices simultaneously. Best for spotting responsive breakpoint issues, comparing layouts, and client presentations. Use our Mobile Viewer for deep single-device inspection.

Why Some URLs Won't Load

Websites using X-Frame-Options: DENY or a restrictive Content-Security-Policy block iframe embedding. For your own site, relax the frame-ancestors directive during development. For sites you don't own, use our Mobile Viewer with the QR Code feature to test on a real device.

FAQ

Frequently Asked Questions

Everything you need to know about the Multi-Device Preview tool

A Multi-Device Preview tool lets you load a single URL and simultaneously view how it renders across multiple screen sizes — mobile, tablet, laptop, and desktop — all in one grid. This lets you instantly compare responsive layouts without switching between browser tabs or simulators one at a time.

Enter your website URL in the input bar at the top and click Load All Devices. The tool instantly renders your website across all active device panels — by default Mobile (375px), Tablet (768px), Laptop (1280px), and Desktop (1440px). You can switch between 2-up, 3-up, and 4-up grid layouts and toggle individual panels on or off.

Yes — 100% free with no registration, no download, and no usage limits. All features including the multi-panel grid, device presets, grid layout toggle, and refresh controls are available to everyone at no cost.

The default four panels are: Mobile (375×812 — iPhone SE/14 viewport), Tablet (768×1024 — iPad), Laptop (1280×800), and Desktop (1440×900). Each panel has its own dropdown with 20+ additional presets including iPhone 15 Pro Max, Samsung Galaxy S23, iPad Pro 11", and Full HD desktop.

Some websites block being loaded inside iframes using the X-Frame-Options or Content-Security-Policy: frame-ancestors HTTP headers. This is a security setting on the target website's server — not a limitation of this tool. For sites you own, you can adjust the frame-ancestors directive to allow iframe embedding during development and testing.

Yes. You can load any URL including http://localhost:3000, a local IP such as http://192.168.1.10:8080, or a private staging server URL. The server must be running and accessible from your browser's network. The same iframe restriction rules apply — your dev server should not be sending X-Frame-Options: DENY.

A single device simulator (like our Mobile Viewer) shows your site in one device frame at a time and is best for detailed inspection of scroll behavior, interactions, and device-specific features. Multi-Device Preview renders all your chosen devices simultaneously in a grid — ideal for catching responsive breakpoint issues, comparing layouts across screen sizes, and producing compelling client deliverables. Both tools complement each other for complete responsive quality assurance.

Free · No Sign-up · Instant

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