Google has unveiled the first public beta of Google Web Designer, its HTML5 web coding tool for Mac and Windows. Although geared towards advertisers looking to build rich interactive web ads using HTML5, CSS3 and JavaScript, Google Web Designer can also be used for a variety of wider applications too.

The app has been launched as part of Google’s drive to make it easier for advertisers to code content for a variety of platforms – mobile and desktop – using HTML5. The idea is that users can simply design the ad and it will work seamlessly across multiple devices with no additional tweaking required.

The current beta – although capable of creating a wider array of single-page web sites – is clearly geared mainly towards advertisers in this initial release, with certain tools unavailable for other uses. It utilises a familiar, design-based user interface that will put those used to DTP and image-editing tools at ease with their work environment.

Create platform-agnostic HTML5 web ads and sites with the help of Google Web Designer.

Despite the user-friendly interface, Google Web Designer is packed with powerful features to help users create 3D content using CSS3, build scene-by-scene animations using timelines and delve directly into the underlying code using a dedicated Code view with syntax highlighting and code auto-completion to help speed things up.

The tool will compete directly with paid-for offerings from the likes of Adobe with its Muse and Edge Reflow products, but has the obvious advantage of being completely free. Google Web Designer Beta is available now as a freeware download for PCs running Windows 7 or later, and Macs running OS X 10.7 (Lion) or later.