Non-advertising performance issues
Before diving into ad performance, make sure your website has top-notch performance when the ads are turned off.
Common practices include using a CDN, optimizing images, setting proper cache lifetimes, enabling compression, reducing HTTP requests, minifying and concatenating scripts and stylesheets, and avoiding synchronous javascript.
Use Lighthouse to check your webpage performance, and use the “Network Request Blocking” feature in Chrome Dev Tools to prevent advertising scripts from loading while you troubleshoot core website performance issues.
Reduce bidders
Reducing the number of bidders will reduce the number of HTTP requests and improve page performance. HTL BID’s slot configuration screens allow you to configure different bidders on mobile/tablet/desktop, and the Traffic Shaping feature allows modifying which bidders run in specific regions and browsers. Publishers may consider running fewer or different bidders on mobile, where bandwidth and processing power is limited. Note that reducing bidders may affect monetization, so consider using A/B tests to measure the impact.
Use Prebid server
Moving bidding activity to the server side can improve page performance by reducing the number of HTTP requests. Learn more about Prebid Server here.
Lower timeouts
Lowering the header bidding timeouts will improve perceived webpage performance by causing ads to finish rendering more quickly. Note that very low timeouts may negatively affect monetization, since bid responses that arrive after the timeout will be rejected. On the other hand, better UX can improvement visitor retention. Consider A/B testing timeout changes.