I have built a website and the masthead uses an SVG that contains the site title, logo and support graphics.
The masthead still contains the logo as an inline image, and
<h2> tags. However the logo and header tags are all hidden using CSS in favour of the masthead graphic.
The HTML shown below may not have been uploaded to the website at the time of writing this question, just in case you're wondering why the source code of the URL is different. But that's what it will look like.
Does this affect SEO? As the HTML does match the masthead content and doesn't contain spam or fake keywords. It also matches the page title in the browser window.
<div class="masthead-inner container"> <a class="logo hidden" href="<?php echo $appurl; ?>" title="All Together"><img src="<?php echo $appurl; ?>img/logo2.png" alt="All Together logo"></a> <h1 class="hidden">All Together - Work Placement Software</h1> <h2 class="hidden">Online software for efficient placement management</h2> </div>