Aspect Ratio

‮A media frame that preserves its width-to-height ratio.‬

‮Browsers‬: Chrome 123+Firefox 121+Safari 17.5+
‮Tier‬: 0
‮Bundle compressed‬: 268 B
‮Forced layout budget‬: 0 ms
‮Axe budget‬: 0
‮SSR compatible‬: ‮Yes‬
‮Published contract‬: ‮Test harness‬

‮Playground‬

16:9 · Cover

An amber sun above overlapping blue mountain ridges

React

CSS

Tailwind

@layer components {
  [data-uiify-aspect-ratio] {
    border-radius: var(--radius-md);
    background: var(--muted);
  }

  [data-uiify-aspect-ratio] > [data-part="content"] {
    border-radius: inherit;
  }

  [data-uiify-aspect-ratio] > [data-part="content"] > img {
    display: block;
    inline-size: 100%;
    block-size: 100%;
    border-radius: inherit;
    object-fit: cover;
  }
}

import { AspectRatio } from "@gunkin/uiify";

export default function Example() {
  return (
    <AspectRatio
      ratio={16 / 9}
      className="
        rounded-md bg-muted [&>[data-part=content]]:[border-radius:inherit] [&>[data-part=content]>img]:block
        [&>[data-part=content]>img]:[inline-size:100%] [&>[data-part=content]>img]:[block-size:100%]
        [&>[data-part=content]>img]:[border-radius:inherit] [&>[data-part=content]>img]:object-cover
      "
    >
      <img src="/mountains.svg" width="640" height="400" alt="An amber sun above blue mountain ridges" />
    </AspectRatio>
  );
}

/* app.css */

@layer reset, ui, app, tokens, base, demo, components, utilities, theme;

@import "@gunkin/uiify/styles/reset";

@import "@gunkin/uiify/components/behavior.css";

@import "@gunkin/uiify/styles/tokens";

@import "@gunkin/uiify/styles/tailwind";

@import "tailwindcss/utilities.css";

@theme { --spacing: 0.25rem; --font-weight-normal: 400; --font-weight-medium: 500; --font-weight-semibold: 600; --font-weight-bold: 700; }

@source inline('rounded-md bg-muted [&>[data-part=content]]:[border-radius:inherit] [&>[data-part=content]>img]:block [&>[data-part=content]>img]:[inline-size:100%] [&>[data-part=content]>img]:[block-size:100%] [&>[data-part=content]>img]:[border-radius:inherit] [&>[data-part=content]>img]:object-cover');

@layer base { :root { --uiify-control-text: var(--text-sm); } @media (pointer: coarse) { :root { --uiify-control-text: var(--text-base); } } }

/* Authored animation and registered properties used by the Tailwind skin.
 * Visual rules belong in utility recipes; only at-rule definitions live here. */
@layer components {
  @keyframes uiify-presence-in {
    from {
      opacity: 0;
      scale: var(--presence-scale);
    }
  }
}

@layer components {
  @keyframes uiify-presence-out {
    to {
      opacity: 0;
      scale: var(--presence-scale);
    }
  }
}

@property --uiify-spinner-tail {
  syntax: "<angle>";
  inherits: false;
  initial-value: 0deg;
}

@property --uiify-spinner-length {
  syntax: "<angle>";
  inherits: false;
  initial-value: 36deg;
}

@layer components {
  @keyframes uiify-spinner-rotate {
    to {
      transform: rotate(360deg);
    }
  }
}

@layer components {
  @keyframes uiify-spinner-orbit {
    0% {
      --uiify-spinner-tail: 0deg;
      --uiify-spinner-length: 36deg;
    }

    50% {
      --uiify-spinner-tail: 90deg;
      --uiify-spinner-length: 324deg;
    }

    100% {
      --uiify-spinner-tail: 360deg;
      --uiify-spinner-length: 36deg;
    }
  }
}

@layer components {
  @keyframes uiify-skeleton-pulse {
    50% {
      opacity: 0.45;
    }
  }
}

@layer components {
  @keyframes uiify-skeleton-shimmer {
    to {
      background-position: -200% 0;
    }
  }
}

@layer components {
  @keyframes uiify-skeleton-reveal {
    from {
      opacity: 0;
    }
    to {
      opacity: 1;
    }
  }
}

@property --candle-body-height {
  syntax: "<percentage>";
  inherits: true;
  initial-value: 0%;
}

@property --candle-body-top {
  syntax: "<percentage>";
  inherits: true;
  initial-value: 50%;
}

@property --candle-slot {
  syntax: "<percentage>";
  inherits: true;
  initial-value: 100%;
}

@property --candle-wick-height {
  syntax: "<percentage>";
  inherits: true;
  initial-value: 0%;
}

@property --candle-wick-top {
  syntax: "<percentage>";
  inherits: true;
  initial-value: 50%;
}

@property --candle-x {
  syntax: "<percentage>";
  inherits: true;
  initial-value: 0%;
}

@property --candle-scale {
  syntax: "<number>";
  inherits: true;
  initial-value: 1;
}

@property --line-y {
  syntax: "<percentage>";
  inherits: true;
  initial-value: 50%;
}

@property --line-prev-y {
  syntax: "<percentage>";
  inherits: true;
  initial-value: 50%;
}

@property --line-count {
  syntax: "<integer>";
  inherits: false;
  initial-value: 1;
}

@property --line-scale {
  syntax: "<number>";
  inherits: true;
  initial-value: 1;
}

@layer components {
  @keyframes uiify-otp-input-caret-blink {
    50% {
      opacity: 0;
    }
  }
}

‮Examples‬

Square

The default ratio is 1. A square frame crops a landscape image at the sides.

import { AspectRatio } from "@gunkin/uiify";

<AspectRatio>
  <img src="/mountains.svg" width="640" height="400" alt="An amber sun above blue mountain ridges" />
</AspectRatio>

Portrait

Set ratio to 4 / 5 for a portrait frame. The image keeps its proportions while filling the frame.

import { AspectRatio } from "@gunkin/uiify";

<AspectRatio ratio={4 / 5}>
  <img src="/mountains.svg" width="640" height="400" alt="An amber sun above blue mountain ridges" />
</AspectRatio>

Contain

Apply .uncropped { object-fit: contain; } to keep the whole image visible. The optional skin supplies the frame background.

import { AspectRatio } from "@gunkin/uiify";

<AspectRatio ratio={16 / 9}>
  <img className="uncropped" src="/mountains.svg" width="640" height="400" alt="An amber sun above blue mountain ridges" />
</AspectRatio>

‮API‬

`AspectRatio`

‮Prop‬	‮Type‬	‮Default‬	‮Description‬
`ratio`	`number`	`1`	‮Positive finite width divided by height. Invalid numbers fall back to 1. When omitted, the CSS custom property can set the ratio.‬
`children`	`ReactNode`	—	‮Content placed inside the frame. Intrinsic content cannot enlarge the frame.‬
`className`	`string`	—	‮Class applied to the frame root.‬
`style`	`CSSProperties`	—	‮Native root styles, including --uiify-aspect-ratio when ratio is omitted.‬
`ref`	`Ref<HTMLElement>`	—	‮Ref forwarded to the rendered root element.‬
`as`	`ElementType`	`"div"`	‮Native element or component used for the root.‬
`render`	`ReactElement \| ((props, state) => ReactElement)`	—	‮Replace the rendered root while preserving its props, ref and identity marker.‬

‮Keyboard‬

‮Key‬	‮Action‬

‮Accessibility‬

‮Static layout adds no role, focus target or keyboard behavior. Give meaningful images alt text; keep captions outside the frame. Required behavior CSS preserves the ratio even when children have intrinsic dimensions. Optional styles fill images with object-fit: cover; use contain to show the entire image.‬

‮Styling hooks‬

data-uiify-aspect-ratiodata-part="content"--uiify-aspect-ratio

‮Framework‬

‮Style‬

‮Theme‬

‮Language‬