visibility:hidden vs display:none vs opacity:0

While all 3 properties make an element's box seem invisible, there are crucial differences between them:

• The "Painted" column indicates if the browser will paint the element's background (e.g. background-image), #text content, and so on.
  • An element cannot be painted without also participating in the page's layout, of course.
  • This is No for all 3 properties and values, as the browser won't need to paint the element's box as it's invisible.
• The "In layout" column indicates if the browser will compute the layout and dimensions of the element - along with any of its descendants not excluded from layout.
  • This is only No for display: none;, as with opacity: 0; and visibility: hidden; the browser will still determine the size of the element so it can correctly layout other elements relative to the current element (e.g. if you have span.hidden { visibility: hidden; display: inline; }).
• The "Stacking context" column indicates that any use of opacity (except opacity: 1.0;) will create a new stacking-context, which complicates use of the position property.
• The "Pointer events" column indicates if the element will respond to user-interaction from a pointing device, such as a mouse, touch-screen, stylus, etc.
  • e.g. with visibility: hidden; then the :hover state won't work, and clicking the same element won't apply :focus or :active either.
  • Additionally, the DOM won't raise any pointer events you'd handle in JavaScript (e.g. visibility: hidden; won't raise mouseclick, touchstart, etc - note that the click event can still be raised by certain elements, like <button> if invoked by the user using a non-pointer input method, such as with keyboard or voice (accessible) navigation means.
    • You can use pointer-events: none; to block pointer events, but this won't block keyboard and other non-pointer input and so should not be used to disable an element because the user can still use the keyboard to interact with it (especially <button>, <input />, <select>, and <textarea>).
• The "Keyboard events" column indicates if the element can be interacted-with using keyboard navigation (and possibly other navigation means).
  • This includes smart-device (smartphones' and tablets') browsers' "Prev/Next Field" buttons for navigating <form> elements (as this uses tabindex).
  • Unlike how pointer-events can be disabled in CSS using pointer-events: none;, there is no CSS property to disable keyboard interaction.

This table shows a more complete comparison between the main values of those 3 properties:

• The "Animatable" column indicates if that property can be used with a CSS transition (transition:) or CSS animation (@keyframes).

  • Crucially, the display: property cannot be animated, which is why we can't use a @keyframes timeline to completely hide an element after the animation is complete.
    • But curiously, we can animate the visibility: property despite being non-continuous, albeit with caveats.

• Also, don't get confused by the similarly-named backface-visibility and content-visibility properties.

  • backface-visibility is only applicable to 3D transform operations.
  • content-visibility is an optimization to speed-up page rendering during initial page-load, but requires CSS Containment first, which is out-of-scope for this QA.

The answer found here will answer your first question (most likely display:none as the space is collapsed completely).

To your second question, tools such as this will probably be useful for you. However 40,000 divs sounds like way too many and you will probably have better performance using canvas or SVG (for example, using the KineticJS library as this handles animations - transformation, rotation, scale, etc.) for you.

Performance will be an issue if display:none or visibility:hidden is used since they trigger paint and layout in most browsers which means your browser will redraw the viewport whenever those two changes so I will recommend opacity but still for that number of divs it will still be not performant as expected you can try webgl using a library called html-gl which render your divs in webgl check https://github.com/PixelsCommander/HTML-GL

Here is a compilation of verified information from the various answers.

Each of these CSS properties is in fact unique. In addition to rendering an element not visible, they have the following additional effect(s):

1. Collapses the space that the element would normally occupy
2. Responds to events (e.g., click, keypress)
3. Participates in the taborder

                     collapse events taborder
opacity: 0              No     Yes     Yes
visibility: hidden      No     No      No
visibility: collapse    *      No      No
display: none          Yes     No      No

* Yes inside a table element, otherwise No.

got from link