switch·Esc back

Z-Index

You might say

This dialog is getting covered by other content. Make sure it stays on top.

Control which overlapping layer appears on topZ-index affects the stacking order of positioned elements inside a stacking context. A larger number does not always escape its parent. Define a short layer scale for content, sticky UI, menus, overlays, and dialogs instead of solving each overlap with a larger random number.
Know first
z: 1 z: 2 z: 3

When to use it

  • Keep a dropdown above nearby content
    Delete this project?
    CancelDelete
  • Place a dialog above its backdrop
  • Order sticky and floating elements
  • Create a shared layer scale

When NOT to use it

  • Keep increasing the number without checking the stacking context
  • Give every component its own arbitrary z-index
  • Place ordinary content above a modal
  • Use layering to hide a layout or clipping problem
Anatomy
z-index: 1z-index: 2The big one is on top
The z-index is small and is suppressed below.
The z-index is larger and covers it.
The stacking value used to position elements and flex/grid items; it also depends on the stacking context in which it is located.
Variants
1 ~ 10
12
The card corner mark and avatar are slightly overlaid.
100
100
Fixed bar suppresses scrolling content
1000
Page1000
Drop-down, bubble, text prompt
10000
10000
Example gear: Make the modal layer higher than the ordinary page floating layer
Typical use cases
Dropdown layer
Page z-index: 1
Mask z-index: 1000
Pop-up z-index: 1001 Confirm to log out?
Sticky header
Document Center Guidelines API z-index: 100
In the same cascading rule, the navigation level is higher than the scrolling content
Modal
Task list In progress ▾
z-index: 1000
All
In progress ✓
Completed
The drop-down floats on top of the card and is neither covered nor cut
Tooltip
z-index: 10
Further reading