Calculate aspect ratios, legacy padding-top hacks, and modern CSS aspect-ratio rules.
Execution runs 100% locally inside the browser sandbox using HTML5 Canvas, Web Cryptography Subtle API, and Web Workers. Zero egress.
Zero network latency. Operates completely offline with zero dependencies on third-party backend servers or cloud services.
Built according to official RFC specifications, cryptographic test vectors, and enterprise-grade data transformation standards.
Select standard presets like 16:9, 4:3, 1:1, 9:16, 21:9, or enter custom width/height.
Preview how the element resizes responsively while locking its proportional aspect ratio.
Copy modern aspect-ratio rules or legacy padding-top container stylesheets.
In CSS, percentage padding is calculated relative to the parent container's width, allowing (Height / Width * 100)% to maintain fixed proportions.
Yes, the native aspect-ratio property is supported in all modern versions of Chrome, Safari, Firefox, and Edge.
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