[{"data":1,"prerenderedAt":64},["ShallowReactive",2],{"\u002Fglossary\u002Fanti-flicker-script":3,"\u002Fglossary\u002Fanti-flicker-script:related":47},{"id":4,"title":5,"author":6,"authorImage":7,"body":8,"category":32,"date":33,"description":34,"draft":35,"extension":36,"letter":37,"meta":38,"navigation":39,"path":40,"readTime":41,"related":42,"seo":43,"stem":45,"term":5,"__hash__":46},"glossary\u002Fglossary\u002Fanti-flicker-script.md","Anti-Flicker Script","Fabian Krumbholz","\u002Fimages\u002Fauthors\u002Ffabian-krumbholz.webp",{"type":9,"value":10,"toc":28},"minimark",[11],[12,13,14,15,19,20,23,24,27],"p",{},"An anti-flicker script is a piece of JavaScript used by many ",[16,17,18],"strong",{},"Client-Side A\u002FB Testing"," tools. Its purpose is to prevent the ",[16,21,22],{},"Flicker Effect",", where a user briefly sees the original page before the test version loads and replaces it. The script works by hiding the entire page content until the test variation is ready to be displayed. While this solves the flicker, it introduces a significant performance penalty by forcing the user to look at a blank screen, which negatively impacts crucial metrics like ",[16,25,26],{},"Largest Contentful Paint (LCP)",".",{"title":29,"searchDepth":30,"depth":30,"links":31},"",2,[],null,"September 30, 2025","An anti-flicker script is a piece of JavaScript used by many Client-Side A\u002FB Testing tools. Its purpose is to prevent the Flicker Effect, where a user briefly sees the original page before the test…",false,"md","A",{},true,"\u002Fglossary\u002Fanti-flicker-script","1 min read",[],{"title":44,"description":34},"Anti-Flicker Script: Definition | Web Performance Glossary","glossary\u002Fanti-flicker-script","mXfriwXm2z-n4wqOt40xfcSd-HQ1ouKFjMyUwo3fjR4",[48,52,56,60],{"path":49,"title":50,"description":51,"letter":37},"\u002Fglossary\u002Fa-b-testing","A\u002FB Testing","A\u002FB testing is a method of comparing two versions of a webpage to see which one performs better. For example, an e-commerce store might show 50% of its visitors a green \"Buy Now\" button (Version A)…",{"path":53,"title":54,"description":55,"letter":37},"\u002Fglossary\u002Favif","AVIF","AVIF (AV1 Image File Format) is a modern, next-generation image format that provides significantly better compression than older formats like JPEG and WebP.",{"path":57,"title":58,"description":59,"letter":37},"\u002Fglossary\u002Fabandonment-rate","Abandonment Rate","Abandonment Rate is a metric that measures the percentage of users who start a specific process (like a checkout funnel or a sign-up form) but leave before completing it.",{"path":61,"title":62,"description":63,"letter":37},"\u002Fglossary\u002Fabove-the-fold","Above the Fold","This is a term originally from newspaper design that now refers to the portion of a webpage that is visible to a user without having to scroll down. Content \"above the fold\" is the very first thing a user sees.",1787756711609]