Each Friday Yottaa CTO Bob Buffone digs into the data and evaluates the web performance of a new website.  Recommend a site for next week’s Expert Eval in the comments below or @Yottaa on Twitter! #ExpertEval

In his post yesterday, Alex talked a little bit about the OBA (one bad asset).  What is OBA and why should you care?

OBA, or one bad asset, is the asset with the longest time-to-last byte in your page loading sequence.

OBAs can slow down even the best-optimized sites if they’re not watched for.  But why read the definition when you could see an example!  As you’ll see in the waterfall below, the website MossyOakGraphics.com has an OBA problem that they will need to fix in order to solve their performance issues. (Click the image to enlarge or click here for the full waterfall)

A single JavaScript asset related to the company’s chat functionality, (pictured as the long tan-colored row above)  takes over 4 seconds to load, which equals 55% of the page load time of 7.2 seconds. This is a big problem because the asset is a blocking Javascript resource. This causes other resources to be blocked. You can see this effect in action in the image below.

How can MossyOakGraphics.com get around this pernicious issue?

When fixing an OBA, the solution always depends on the type of asset at hand. In the case shown here, with JavaScript, they will either need to 1.) talk to their chat widget provider and make them upgrade their service to a better level; or 2.) asynchronously load the JavaScript using one of the many techniques that have been identified do so. StackOverflow.com is a great resource for tips on subjects like this.

In addition to this OBA, MossyOakGraphics.com could also stand to optimize their background image, which is a whopping 1.2MB.  Likewise they could cut down the number of JavaScript files the site loads (currently at 31) through concatenation, minification, and compression.

We will be sharing more data about OBA in upcoming posts.  In the meantime, use Yottaa to see what asset might be your website’s OBA.

Bob (Buffone)