How to Make a Curved Edge Hexagon by Using Css

How to make a curved edge hexagon by using CSS

I think you are looking for this.

.hex {
  position: relative;
  margin: 1em auto;
  width: 10em;
  height: 17.32em;
  border-radius: 1em/.5em;
  background: orange;
  transition: opacity .5s;
}

.hex:before,
.hex:after {
  position: absolute;
  width: inherit;
  height: inherit;
  border-radius: inherit;
  background: inherit;
  content: '';
}

.hex:before {
  -webkit-transform: rotate(60deg);
  transform: rotate(60deg);
}

.hex:after {
  -webkit-transform: rotate(-60deg);
  transform: rotate(-60deg);
}

<div class="hex"></div>

Make hexagon shape with border, rounded corners and transparent background

Hexagon with rounded corners are complex shapes to create and I usually recommend using SVG for creating them. The need for a transparent background makes it even more better suited for SVG. With SVG you can get better control over the shape, its curves etc and you don't have to add a lot of extra (unnecessary) elements to your markup also.

All that is needed for creating this shape with SVG is to use a single path element along with a few L (line) and A (arc) commands. The L (line) command basically draws a line from point 1 to point 2 whereas the A (arc) command draws an arc of the specified radius (the first two values immediately following the A command).

You can read more about the SVG path element and its commands in this MDN tutorial.

svg {  height: 200px;  width: 240px;}path {  stroke: #777;  fill: none;}
body {  background: black;}

<svg viewBox='0 0 120 100'>  <path d='M38,2            L82,2            A12,12 0 0,1 94,10            L112,44            A12,12 0 0,1 112,56           L94,90                  A12,12 0 0,1 82,98           L38,98           A12,12 0 0,1 26,90           L8,56           A12,12 0 0,1 8,44           L26,10           A12,12 0 0,1 38,2' /></svg>

How to make a hexagonal SVG shape Rounded corner?

Use stroke-linejoin: round in path to round corner

let max = 2160;
let progress = 80;
document.querySelector(".fill").setAttribute(
  "style",
  "stroke-dashoffset: " + ((100 - progress) / 100) * max
);

.user-avatar-holder{
    background: #1D2333;
    width: 500px;
    height: 500px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 25px auto;
    clip-path: polygon(
        47.5% 5.66987%,
        48.2899% 5.30154%,
        49.13176% 5.07596%,
        50% 5%,
        50.86824% 5.07596%,
        51.7101% 5.30154%,
        52.5% 5.66987%,
        87.14102% 25.66987%,
        87.85495% 26.16978%,
        88.47124% 26.78606%,
        88.97114% 27.5%,
        89.33948% 28.2899%,
        89.56505% 29.13176%,
        89.64102% 30%,
        89.64102% 70%,
        89.56505% 70.86824%,
        89.33948% 71.7101%,
        88.97114% 72.5%,
        88.47124% 73.21394%,
        87.85495% 73.83022%,
        87.14102% 74.33013%,
        52.5% 94.33013%,
        51.7101% 94.69846%,
        50.86824% 94.92404%,
        50% 95%,
        49.13176% 94.92404%,
        48.2899% 94.69846%,
        47.5% 94.33013%,
        12.85898% 74.33013%,
        12.14505% 73.83022%,
        11.52876% 73.21394%,
        11.02886% 72.5%,
        10.66052% 71.7101%,
        10.43495% 70.86824%,
        10.35898% 70%,
        10.35898% 30%,
        10.43495% 29.13176%,
        10.66052% 28.2899%,
        11.02886% 27.5%,
        11.52876% 26.78606%,
        12.14505% 26.16978%,
        12.85898% 25.66987%
    );
    position: relative;
    overflow: hidden;
}
.profile-image-outer{
    background: #1D2333;
    width: 360px;
    height: 360px;
    clip-path: polygon(
        47.5% 5.66987%,
        48.2899% 5.30154%,
        49.13176% 5.07596%,
        50% 5%,
        50.86824% 5.07596%,
        51.7101% 5.30154%,
        52.5% 5.66987%,
        87.14102% 25.66987%,
        87.85495% 26.16978%,
        88.47124% 26.78606%,
        88.97114% 27.5%,
        89.33948% 28.2899%,
        89.56505% 29.13176%,
        89.64102% 30%,
        89.64102% 70%,
        89.56505% 70.86824%,
        89.33948% 71.7101%,
        88.97114% 72.5%,
        88.47124% 73.21394%,
        87.85495% 73.83022%,
        87.14102% 74.33013%,
        52.5% 94.33013%,
        51.7101% 94.69846%,
        50.86824% 94.92404%,
        50% 95%,
        49.13176% 94.92404%,
        48.2899% 94.69846%,
        47.5% 94.33013%,
        12.85898% 74.33013%,
        12.14505% 73.83022%,
        11.52876% 73.21394%,
        11.02886% 72.5%,
        10.66052% 71.7101%,
        10.43495% 70.86824%,
        10.35898% 70%,
        10.35898% 30%,
        10.43495% 29.13176%,
        10.66052% 28.2899%,
        11.02886% 27.5%,
        11.52876% 26.78606%,
        12.14505% 26.16978%,
        12.85898% 25.66987%
    );
    position: relative;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
}
.profile-image{
    background: #1D2333;
    width: 340px;
    height: 340px;
    clip-path: polygon(
        47.5% 5.66987%,
        48.2899% 5.30154%,
        49.13176% 5.07596%,
        50% 5%,
        50.86824% 5.07596%,
        51.7101% 5.30154%,
        52.5% 5.66987%,
        87.14102% 25.66987%,
        87.85495% 26.16978%,
        88.47124% 26.78606%,
        88.97114% 27.5%,
        89.33948% 28.2899%,
        89.56505% 29.13176%,
        89.64102% 30%,
        89.64102% 70%,
        89.56505% 70.86824%,
        89.33948% 71.7101%,
        88.97114% 72.5%,
        88.47124% 73.21394%,
        87.85495% 73.83022%,
        87.14102% 74.33013%,
        52.5% 94.33013%,
        51.7101% 94.69846%,
        50.86824% 94.92404%,
        50% 95%,
        49.13176% 94.92404%,
        48.2899% 94.69846%,
        47.5% 94.33013%,
        12.85898% 74.33013%,
        12.14505% 73.83022%,
        11.52876% 73.21394%,
        11.02886% 72.5%,
        10.66052% 71.7101%,
        10.43495% 70.86824%,
        10.35898% 70%,
        10.35898% 30%,
        10.43495% 29.13176%,
        10.66052% 28.2899%,
        11.02886% 27.5%,
        11.52876% 26.78606%,
        12.14505% 26.16978%,
        12.85898% 25.66987%
    );
    position: relative;
    overflow: hidden;
}
.profile-image img{
    width: 100%;
    height: 100%;
    object-fit: cover;
}
.progress-bar {
    position: absolute;
    top: 50%;
    background: transparent;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 400px;
    height: 400px;
    margin-top: -5px;
}
.progress {
    width: 100%;
    height: 100%;
    background: transparent;
}
.progress .track,
.progress .fill {
    fill: rgba(0, 0, 0, 0);
    stroke-width: 30;
    transform: translate(75px, 685px) rotate(-90deg);
}
.progress .track {
    stroke: #293249;
}
.progress .fill {
    stroke: #5BD853;
    stroke-linecap: round;
    stroke-dasharray: 2160;
    stroke-dashoffset: 2160;
    transition: stroke-dashoffset 1s;
    stroke-linejoin: round; /*Added this css*/
}
.progress.blue .fill {
    stroke: #5BD853;
    stroke-linejoin: round; /*Added this css*/
}

<div class="user-avatar-holder">
        <div class="progress-bar">
            <svg class="progress blue noselect" x="0px" y="0px" viewBox="0 0 776 628">
                <path class="track" d="M723 314L543 625.77 183 625.77 3 314 183 2.23 543 2.23 723 314z"></path>
                <path class="fill" d="M723 314L543 625.77 183 625.77 3 314 183 2.23 543 2.23 723 314z"></path>
            </svg>
        </div>
        <div class="profile-image-outer">
            <div class="profile-image">
                <img src="https://images.pexels.com/photos/1025804/pexels-photo-1025804.jpeg?auto=compress&cs=tinysrgb&h=350" alt="Sample Image" width="500" height="500" >
            </div>
        </div>
    </div>

Making a hexagon with a mask and border in css3

I would consider my previous answer where I will duplicate the shape to create the border:

.hex {
  position:relative;
  --s:200px;
  width: 200px;
  height:calc(0.866*var(--s));
}

.hex div {
  filter: url('#goo');
  position:absolute;
  inset:0;
}

.hex div::before{
  content: "";
  position:absolute;
  inset:0;
  background:#000;
  clip-path: polygon(25% 0%, 75% 0%, 100% 50%, 75% 100%, 25% 100%, 0% 50%);
}
.hex div:nth-child(2)::before{
  background:red;
  inset:4px;
}

<div class="hex">
  <div></div>
  <div></div>
</div>

<svg style="visibility: hidden; position: absolute;" width="0" height="0" xmlns="http://www.w3.org/2000/svg" version="1.1">
  <defs>
        <filter id="goo"><feGaussianBlur in="SourceGraphic" stdDeviation="8" result="blur" />    
            <feColorMatrix in="blur" mode="matrix" values="1 0 0 0 0  0 1 0 0 0  0 0 1 0 0  0 0 0 19 -9" result="goo" />
            <feComposite in="SourceGraphic" in2="goo" operator="atop"/>
        </filter>
    </defs>
</svg>

How to Make a Curved Edge Hexagon by Using Css