Here at EXADS we are committed to providing the best technologies to help advertisers succeed with campaign performance. In this article we’ll talk about one of these technologies and how it helps campaigns to better reach their target audience: WebP.

But first, we'll need to have a look at how ads are actually delivered, so let's dive into it.

How Ad Serving works?

We talked about how ad servers and ad serving works in a previous post. You can jump and read that article first if you want to have a deeper look at the overall ad serving flow. In this article we’ll focus on a specific part of it and the summary below should be enough for now.

Essentially, when a user visits a Publisher’s website, the browser sends an ad request to the Publisher’s ad server. If the ad request returns a response (an ad), the ad is rendered into the user’s browser.

In order to render the ad - and this is where we’ll put our attention today - the ad’s creatives (image, video) are fetched from the Publisher’s ad server via a CDN.

Once the ad is rendered the impression is tracked. If an end user clicks on the ad then the click is also registered.

You can read more about ad servers and ad serving following our technology posts in our blog.

A brief look at CDNs

Content Delivery Networks (CDN) are virtually transparent to all of us but they play an essential part in the web today.

CDNs solve a problem that we, as tech people, know as latency. In simple terms it's the delay that occurs from the moment the end user requests to load a web page until the moment the content actually appears on-screen.

A CDNs mission is to virtually shorten the physical distance between you and the image / video being downloaded, the goal being to improve site rendering speed and performance.

Another important aspect CDNs fulfill is to enable the platform to scale to massive volumes. Being able to support hundreds of thousands of concurrent end users consuming content all at the same moment.

We recently talked about CDNs and how we use them to deliver ads and ensure the fastest experience to end users. Be sure to take a look at the blog entry to find out more.

Why does it matter?

Similarly to how page speed affects conversion rate, ad delivery affects how fast the ad is rendered into the end user's screen, how it outperforms other ads in the same page and ultimately how quickly it can gain the end user's attention. The slower the ad is to load the less chances it has to catch their attention.

A poor delivery speed translates into low conversion rates for campaigns, which means more money spent with lower results. A no go!

Being able to deliver creatives fast and with the best quality possible is essential for the success of advertiser campaigns and in turn, for successful website monetisation for publishers.

Introducing WebP

WebP is an image file format developed by Google. It combines a set of compression methods in a clever way to obtain the best size-quality combination. It is meant as a replacement to more widely known image formats such as JPG, PNG and GIF; by offering similar features to each of these formats.

WebP offers images around 30% lighter than JPEG with no noticeable quality drop. Additionally, it supports both animation and transparency (as GIF and PNG formats do).

The above 6 images show different quality conversions: the top three are JPEGs and the bottom three are WEBP conversions. Column 1 shows 20% image quality when converting the JPEG to WEBP the image is 33KB ligher at 81KB. Column 2 at 50% quality, converts to 79KB lighter at 159KB with WEBP and and the final column at 80% quality is 189KB ligher at 300KB, 

WebP is a modern image format that provides superior lossless and lossy compression for images on the web. Using WebP, webmasters and web developers can create smaller, richer images that make the web faster. WebP lossless images are 26% smaller in size compared to PNGs. WebP lossy images are 25-34% smaller than comparable JPEG images at equivalent SSIM quality index. Source: https://developers.google.com/speed/webp

What are file formats anyway?

Loosely speaking File formats are methods for storing information. For image formats they can store image information both compressed or uncompressed, camera information (in the case of photos) can be stored as well, some formats even support some form of animation (such as GIF).

One format to rule them all?

Possibly. For the moment we still have to wait for older Operating Systems to forth and take their outdated browsers with them.

According to Caniuse, although stats show around 96% support across browsers and Operating Systems, as a platform, we have to take those 4% into consideration when delivering ads. Since we want to maximize delivery and reach, we don't want to leave anybody without a chance to view the ad creatives! Should you wait for 100% support across all browsers? Not at all. Keep on reading to know why.

EXADS' intelligent delivery of creatives

Since we need to support a wide array of Operating Systems and browsers, we have to balance the latest and greatest technologies with backward compatibility for older platforms.

This is where EXADS' intelligent delivery of creatives comes into the picture.

When advertisers upload their creatives to the EXADS platform we’ll automatically and transparently convert them into the different formats, carefully balancing the quality with the size, to support both newer image formats (such as WebP) and older ones (such as GIF) as well as potentially delivering video rather than animated GIF, which proves to be better performing especially on mobile devices.

This is done in addition to the optimizations we perform on all assets. The only difference is the optimization process doesn’t change the asset format. For example, a JPG image will keep its JPG format - only with a smaller footprint.

In the image below you can see the different processes that are triggered when a new creative is uploaded to the platform:

In the first block from top to bottom the creatives are optimized. As mentioned before, this means the image format will remain the same.

Secondly the conversion process transforms the image format and optimizes the image, substantially reducing its file size.

Finally, and only for animated GIF images, we convert the asset to more modern MP4 or Webm formats. Again, greatly reducing its file size.

But that's not enough! EXADS Ad Serving platform determines support while rendering the ad, offering the best quality with the smallest sized footprint. Falling back to older formats when no support is available.

All of this happens transparently for the advertiser, without having to convert their creatives or figure out browser compatibility!

What's to come?

Technology is constantly evolving, so we don’t know for sure. But at EXADS we’ll keep working to ensure that Publishers and Advertisers using our ad server technology will always be one step ahead of the competition.