Serving less HTML code starting from .NET 4.0 with ClientIDMode property
Knowledge Base Article
One of the best practices in general from performance perspective is to transfer as little data between a client and a server as possible. When it comes to web sites, we need to ensure that the final HTML code is clean and we are not transferring any extra information which is not utilized by the client’s browser at all (e.g. comments in HTML code, unnecessary long control IDs etc.). This article will help you to end up with both cleaner HTML code and optimized performance.