<button type="button" onclick="window.location.href='the link you want the button to take you to'">Click me</button>
<!-- VIA HTML -->
<form action="https://google.com">
<input type="submit" value="Go to Google" />
</form>
<!-- VIA CSS -->
<a href="https://google.com" class="button">Go to Google</a>
a.button {
-webkit-appearance: button;
-moz-appearance: button;
appearance: button;
text-decoration: none;
color: initial;
}
<!-- VIA JAVASCRIPT -->
<input type="button" onclick="location.href='https://google.com';" value="Go to Google" />
button {
background: none!important;
border: none;
padding: 0!important;
/*optional*/
font-family: arial, sans-serif;
/*input has OS specific font-family*/
color: #069;
text-decoration: underline;
cursor: pointer;
}
<form method="link" action="{% url 'gui' %}">
<input type="button" value="Start">
</form>