index.html

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>SVG Viewer</title>
  </head>
  <body>
    <div>
      <input type="file" accept=".svg" onchange="view(event)" />
    </div>
    <div>
      <img id="viewer" alt="请选择图片" style="width: 100vw; height: 90vh; object-fit: contain" />
    </div>
  </body>

  <script>
    function view(e) {
      if (e.target.files.length) {
        let fr = new FileReader();
        fr.onload = (e) => {
          console.log(e.target.result);
          const viewer = document.querySelector("#viewer");
          viewer.src = e.target.result;
        };
        fr.readAsDataURL(e.target.files[0]);
      }
    }
  </script>
</html>