Responsive Tester

Load a URL and switch between phone, tablet, and desktop presets, or set a custom viewport size. Preview a website at common device widths inside an iframe.

Introduction

Responsive Design Tester is a free, browser-based utility in our Design Tools collection. Load a URL and switch between phone, tablet, and desktop presets, or set a custom viewport size. Responsive Design Tester embeds a page in selectable viewports so you can smoke-check layouts quickly. Sites that disallow iframes will appear blank. Everything runs locally in your browser — inputs stay on your device, with no account or upload required. Highlights include device presets.

Features

Device presets
Custom width/height
Iframe preview
One-click load

How to use

1
Enter a URL and click Load.
2
Pick a device preset or custom size.

Example

Phone preset

Input

https://example.com @ 390×844

Output

Framed preview

Benefits

Run Responsive Tester entirely in the browser with no signup or installation.
Keep sensitive sample data private — processing never leaves your device.
Device presets
Custom width/height
Iframe preview
Pair it with Meta Tags and Flexbox Generator when your workflow needs adjacent utilities.

FAQs

The site likely blocks embedding via X-Frame-Options or CSP frame-ancestors.

No. Your browser loads it directly in an iframe.

Only if your browser can reach it and the page allows framing.

Yes. Responsive Tester on EverydayDevTools is free, with no account, watermarks, or usage caps for normal interactive use.

No. Responsive Tester runs in your browser. Your input is processed locally and is not sent to EverydayDevTools servers.

Load a URL and switch between phone, tablet, and desktop presets, or set a custom viewport size. It fits everyday design tools tasks when you want a fast local utility instead of installing a CLI or opening a heavy IDE feature.

Core capabilities include: Device presets; Custom width/height; Iframe preview; One-click load.

Developers often pair Responsive Tester with Meta Tags, Flexbox Generator, Grid Generator. Open Related tools on this page for quick links.