Output

Sample Code

Seamless iframe have some features:

Seamless iframe have no boarder.
Seamless iframe will be affected by css style out of this iframe.
Click a hyperlink inside seamless iframe can open the link out of this iframe.
Other features no list here.

HTML:

<style>
    h1 {
        color: red;
    }
</style>
<h1>Out of iframe</h1>
<br/>
Ordinary iframe:<br/>
<iframe src='seamless-inner.html' width='100%'></iframe>
<br/>
<br/>
Seamless iframe:<br/>
<iframe seamless src='seamless-inner.html'></iframe>