Skip to content
Browse themes
Added 17 Aug 2026
Back to library
envelope-open-icon-15321
Envelope Open Icon
Icons & Shapes

Envelope Open Icon

A CSS envelope whose flap folds back and a lined letter slides up out of it on hover.

Icons & Shapesenvelopemailiconopenhover
lines of CSS
44lines of CSS
dependencies
0dependencies
browser, for years
Everybrowser, for years
motion only on interaction
Hovermotion only on interaction
Backdrop
Open a live copy in

Vue, Svelte, styled-components and Tailwind exports are part of Pro. HTML, CSS and React are free forever.

envelope-open-icon-15321.css
.fx-v12-ic-envelope-15320 {
  position: relative;
  width: 84px;
  height: 60px;
  margin-top: 26px;
  cursor: pointer;
}
.fx-v12-ic-envelope-15320 .body {
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, #38bdf8, #0284c7);
  border-radius: 6px;
  clip-path: polygon(0 0, 50% 45%, 100% 0, 100% 100%, 0 100%);
  z-index: 2;
}
.fx-v12-ic-envelope-15320 .flap {
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 34px;
  background: #0ea5e9;
  clip-path: polygon(0 0, 100% 0, 50% 100%);
  transform-origin: top center;
  transition: transform 0.4s ease;
  z-index: 3;
}
.fx-v12-ic-envelope-15320 .letter {
  position: absolute;
  left: 10px;
  right: 10px;
  top: 6px;
  height: 46px;
  background-color: #f8fafc;
  border-radius: 3px;
  background-image: linear-gradient(#cbd5e1 0 0), linear-gradient(#cbd5e1 0 0), linear-gradient(#cbd5e1 0 0);
  background-size: 60% 3px, 45% 3px, 55% 3px;
  background-position: 8px 10px, 8px 18px, 8px 26px;
  background-repeat: no-repeat;
  transition: transform 0.4s ease 0.1s;
  z-index: 1;
}
.fx-v12-ic-envelope-15320:hover .flap { transform: rotateX(180deg); z-index: 0; }
.fx-v12-ic-envelope-15320:hover .letter { transform: translateY(-26px); }
envelope-open-icon-15321.html
<div class="fx-v12-ic-envelope-15320">
  <span class="letter"></span>
  <span class="flap"></span>
  <span class="body"></span>
</div>

What do I do with this?

  1. Put envelope-open-icon-15321.css anywhere your page already loads CSS from — in Next.js that is app/globals.css, or any stylesheet with a <link> in your HTML.
  2. Then put the class on the element you want it on: <button class="fx-v12-ic-envelope-15320">. The CSS does nothing until a class name in it matches something on the page.
  • Link the stylesheet, then paste the markup wherever you need it.
npx hoverlab add envelope-open-icon-15321

What's included

  • The markup and the stylesheet, in whichever framework you pick
  • No runtime dependencies

Works with

  • React
  • Vue
  • Svelte
  • Tailwind
  • styled-components
  • Plain CSS

npx hoverlab add envelope-open-icon-15321

Or over MCP, from your editor's agent — no account needed.

License

Free to read, copy and install, for personal and non-commercial projects. Shipping it in client work or a paid product needs Pro ($79 once). The source lands in your repo and stops being ours — no attribution, nothing to upgrade.

Was this useful?

Motion safety

Static estimate, read from the CSS

Reduced motion
Brief motion, no guard

Animates briefly or on interaction. Only looping motion gets a guard in this catalog; copy the one from the Insights tab if this ships on a critical path.

What it animates
Compositor only

Only transform, opacity or filter: the GPU can run it without re-laying-out or repainting the page.

Flashing (WCAG 2.3.1)
No flashing found

No repeating change in opacity, colour or brightness large enough to count as a flash.

Layout shift (CLS)
No shift expected

Nothing it animates moves or resizes the box in flow. A category from the CSS, not a measurement for this effect.

Every row is read from the shipped CSS. Only a figure marked measured came from a browser. Customizing the speed changes the timing, so recheck a customized copy. How it is computed

28 more effects in Icons & Shapes

All of them free to read, copy and install — no account, no locked tiles, no watermarked preview. The whole catalog is open, and so are the API and the CLI.

Browse Icons & Shapes

Shipping one commercially

Copying the code is free. Putting it in client work or a paid product is what Pro is for — the licence, not the access.

  • A commercial licence for everything in the catalog
  • Unlimited bundle exports, in Vue, Svelte and Tailwind
  • One payment — no subscription, nothing to renew
Pro — $79 once

7 variations of Envelope Open Icon

Finished looks, each one a position in the customizer above. Copy any of them, or open it and keep moving the sliders.