<p>Is it possible to detect, on the client side, whether the user is using an encrypted page or not?</p>

<p>Put another way -- I want to know if the URL of the current page starts with http or https.</p>

Use
```
window.location.protocol
```
to check if it is
```
https:
```
```
```
function isSecure()
{
   return window.location.protocol == 'https:';
}
```
```
Alternatively you can omit specifying "window" if you don't have a locally scoped location.
```
```
function isSecure()
{
   return location.protocol == 'https:';
}
```
```