Simulate real screen sizes, test live responsive components (bento grids, adaptive headers, pricing cards), inspect breakpoint spectrum transitions, and export production-ready Tailwind v4 @theme, Tailwind v3, CSS Media Query Level 4 range syntax, and CSS Container Queries.

How It Works

  1. Drag the simulated viewport width slider or select any physical device preset (iPhone, iPad, MacBook).
  2. Watch the live bento grid and adaptive navigation bar dynamically morph across breakpoint thresholds.
  3. Review the glowing needle on the Breakpoint Spectrum ruler to verify threshold coverage.
  4. Choose your framework export format (Tailwind v4, CSS Container Queries, React hook) and click Copy Snippet.

Frequently Asked Questions

How do CSS Container Queries differ from Viewport Media Queries?

Viewport media queries (@media) evaluate the entire browser window width. CSS Container Queries (@container) evaluate the width of the parent container holding the component, allowing micro-frontends and reusable UI widgets to be truly modular regardless of where they are placed on the page.

What is modern CSS Media Query Level 4 range syntax?

Instead of writing clunky @media (min-width: 768px) and (max-width: 1023px), modern browsers support math range syntax: @media (768px <= width < 1024px) or @media (width >= 768px), which is cleaner, less error-prone, and supported in all modern engines.

How do I use the Tailwind CSS v4 @theme breakpoint configuration?

Tailwind v4 replaces tailwind.config.js with CSS-first configuration using @theme { --breakpoint-sm: 40rem; --breakpoint-md: 48rem; }. You can copy this snippet directly from our studio into your global CSS entry file.

Does this tool support physical device DPR (Device Pixel Ratio)?

Yes! Our device matrix displays CSS viewport points, device pixel ratio (e.g., 3.0x on iPhone 16 Pro, 2.0x on Retina displays), and total physical hardware pixels to ensure your responsive assets render razor sharp.

Air-Gapped Client-Side Processing

FrontendYogi processes all code, text, documents, and media entirely inside your browser memory. No data is logged, uploaded, or transmitted to any remote servers.