> For the complete documentation index, see [llms.txt](https://helps.ptengine.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://helps.ptengine.com/en/faq/experience-edit/anti-flicker.md). # Flicker Phenomenon and How to Address It ## Flicker Phenomenon and How to Address It ## What is Flicker Phenomenon Flicker phenomenon occurs when a page is loading and briefly displays the content before changes, then displays the content after changes. Flicker tends to occur when conducting A/B tests or redirect tests. ## How to Reduce Flicker Phenomenon #### Step 1: Install Ptengine Basic Tag Ptengine's basic tag contains the logic for the anti-flicker feature. Therefore, we recommend placing it in the page's `` to ensure it functions at an early timing. #### Step 2: Configure in Ptengine Admin Panel **1. What is the Anti-Flicker Feature** It is a feature that mitigates flicker phenomenon. In the Ptengine experience's settings screen, you can set the anti-flicker feature to "on/off". This feature is Off by default, but when turned On, it hides the flicker phenomenon with a white-out. **2. When Should You Enable the Anti-Flicker Feature** \[Quick Reference] Summary of Recommended Settings > **WARNING** **Note**: When multiple experiences are published on the same page, the flicker prevention effect works as long as one experience has the anti-flicker setting enabled. ### When You Cannot Install Ptengine Tag Directly in Head #### 1. Phenomenon and Cause When the tag is installed via GTM (Google Tag Manager) or the basic tag is placed inside the HTML ``, the anti-flicker feature may not work properly. This is because the execution of the Ptengine tag is delayed due to "asynchronous loading," which prioritizes page display speed. As a result, unnatural display occurs (original page → white screen → edited page), which may harm user experience. #### 2. Solution To solve this problem, keep the **existing basic tag as is** and add a **dedicated anti-flicker tag** following the steps below. **① Install the dedicated tag in ``** Place the following dedicated anti-flicker tag directly inside the `` of your website's HTML source code. `` > **WARNING** \*Note: xxxxxxxx is the project ID and matches the ID of the basic tag. **② Enable the feature on the Ptengine side** Set the anti-flicker feature to "On" in the Ptengine admin panel. > **WARNING** **Notes** > > The anti-flicker tag timeout is **4 seconds**. > > If the page load speed itself is extremely slow, flicker may still occur even after the above configuration. Therefore, we recommend installing the Ptengine tag directly in the head whenever possible. ## Summary Flicker prevention settings vary depending on how the tag is installed. **Recommended: When installing directly inside ``** Install Ptengine's **basic tag** and turn on the anti-flicker feature **ON**. **When installing via GTM, etc.: Install the dedicated anti-flicker tag** additionally in `` and turn on the anti-flicker feature **ON**. See the table below for details on each setting and its effects. \*When installing the basic tag directly, no separate anti-flicker tag is needed.