how to remove button outline in css code example

Example 1: css remove blue outline button

button {
  outline: none;
}

Example 2: diable focus button css

*:focus {
    outline: 0 !important;
}

Example 3: css remove button outline

button:focus {outline:0;}

Example 4: remove outline on button click

using outline:none; we can remove that border in chrome

for tailwind css :
outline-none 
focus:outline-none

Example 5: remove button outlines

<button class="btn shadow-none">Bootstrap (4.1) button without shadow</button>