content-visibility

visible

No effect. The element's contents are laid out and rendered as normal.

hidden

The element skips its contents. The skipped contents must not be accessible to user-agent features, such as find-in-page, tab-order navigation, etc., nor be selectable or focusable. This is similar to giving the contents display: none.

auto

The element turns on layout containment, style containment, and paint containment. If the element is not relevant to the user, it also skips its contents. Unlike hidden, the skipped contents must still be available as normal to user-agent features such as find-in-page, tab order navigation, etc., and must be focusable and selectable as normal.

Supporting browsers animate/transition content-visibility with a variation on the discrete animation type.

Discrete animation generally means that the property will flip between two values 50% of the way through the animation. In the case of content-visibility, however, the browser will flip between the two values to show the animated content for the entire animation duration. So, for example:

• When animating content-visibility from hidden to visible, the value will flip to visible at 0% of the animation duration so it is visible throughout.
• When animating content-visibility from visible to hidden, the value will flip to hidden at 100% of the animation duration so it is visible throughout.

This behavior is useful for creating entry/exit animations where you want to, for example, remove some content from the DOM with content-visibility: hidden, but you want a smooth transition (such as a fade-out) rather than it disappearing immediately.

When animating content-visibility with CSS transitions, transition-behavior: allow-discrete needs to be set on content-visibility. This effectively enables content-visibility transitions.

content-visibility = 
visible  |
auto     |
hidden   

Off-screen content within a content-visibility: auto property remains in the document object model and the accessibility tree. This allows improving page performance with content-visibility: auto without negatively impacting accessibility.

Since styles for off-screen content are not rendered, elements intentionally hidden with display: none or visibility: hidden will still appear in the accessibility tree. If you don't want an element to appear in the accessibility tree, use aria-hidden="true".

The following example shows the use of content-visibility: auto to skip painting and rendering of off-screen sections. When a section is out of the viewport then the painting of the content is skipped until the section comes close to the viewport, this helps with both load and interactions on the page.

HTML

<section>
  <!-- Content for each section… -->
</section>
<section>
  <!-- Content for each section… -->
</section>
<section>
  <!-- Content for each section… -->
</section>
<!-- … -->

CSS

The contain-intrinsic-size property adds a default size of 500px to the height and width of each section element. After a section is rendered, it will retain its rendered intrinsic size, even when it is scrolled out of the viewport.

section {
  content-visibility: auto;
  contain-intrinsic-size: auto 500px;
}

The following example shows how to manage content visibility with JavaScript. Using content-visibility: hidden; instead of display: none; preserves the rendering state of content when hidden and rendering is faster.

HTML

<div class="hidden">
  <button class="toggle">Show</button>
  <p>
    This content is initially hidden and can be shown by clicking the button.
  </p>
</div>
<div class="visible">
  <button class="toggle">Hide</button>
  <p>
    This content is initially visible and can be hidden by clicking the button.
  </p>
</div>

CSS

The content-visibility property is set on paragraphs that are direct children of elements with the visible and hidden classes. In our example, we can show and hide content in paragraphs depending on the CSS class of parent div elements.

The contain-intrinsic-size property is included to represent the content size. This helps to reduce layout shift when content is hidden.

p {
  contain-intrinsic-size: 0 1.1em;
  border: dotted 2px;
}

.hidden > p {
  content-visibility: hidden;
}

.visible > p {
  content-visibility: visible;
}

JavaScript

const handleClick = (event) => {
  const button = event.target;
  const div = button.parentElement;
  button.textContent = div.classList.contains("visible") ? "Show" : "Hide";
  div.classList.toggle("hidden");
  div.classList.toggle("visible");
};

document.querySelectorAll("button.toggle").forEach((button) => {
  button.addEventListener("click", handleClick);
});

Result

In this example, we have a <div> element, the content of which can be toggled between shown and hidden by clicking or pressing any key.

HTML

<p>
  Click anywhere on the screen or press any key to toggle the
  <code>&lt;div&gt;</code> content between hidden and showing.
</p>

<div>
  This is a <code>&lt;div&gt;</code> element that animates between
  <code>content-visibility: hidden;</code>and
  <code>content-visibility: visible;</code>. We've also animated the text color
  to create a smooth animation effect.
</div>

CSS

In the CSS we initially set content-visibility: hidden; on the <div> to hide its content. We then set up @keyframe animations and attach them to classes to show and hide the <div>, animating content-visibility and color so that you get a smooth animation effect as the content is shown/hidden.

div {
  font-size: 1.6rem;
  padding: 20px;
  border: 3px solid red;
  border-radius: 20px;
  width: 480px;

  content-visibility: hidden;
}

/* Animation classes */

.show {
  animation: show 0.7s ease-in forwards;
}

.hide {
  animation: hide 0.7s ease-out forwards;
}

/* Animation keyframes */

@keyframes show {
  0% {
    content-visibility: hidden;
    color: rgb(0 0 0 / 0%);
  }

  100% {
    content-visibility: visible;
    color: rgb(0 0 0 / 100%);
  }
}

@keyframes hide {
  0% {
    content-visibility: visible;
    color: rgb(0 0 0 / 100%);
  }

  100% {
    content-visibility: hidden;
    color: rgb(0 0 0 / 0%);
  }
}

JavaScript

Finally, we use JavaScript to apply the .show and .hide classes to the <div> as appropriate to apply the animations as it is toggled between shown and hidden states.

const divElem = document.querySelector("div");
const htmlElem = document.querySelector(":root");

htmlElem.addEventListener("click", showHide);
document.addEventListener("keydown", showHide);

function showHide() {
  if (divElem.classList[0] === "show") {
    divElem.classList.remove("show");
    divElem.classList.add("hide");
  } else {
    divElem.classList.remove("hide");
    divElem.classList.add("show");
  }
}

Result

The rendered result looks like this:

• CSS Containment
• contain-intrinsic-size
• contentvisibilityautostatechange
• content-visibility: the new CSS property that boosts your rendering performance (web.dev)