# Tag V4: Boost Your User Experience with an Improved Modification Engine!

At AB Tasty, we are committed to providing our clients with the best possible experience by making it easier to create and execute their optimization campaigns. That’s why we recently made significant improvements to our "Modification Engine," one of the core components of our visual editor and our JavaScript tag.

This update brings two major advancements:

* **Maximum compatibility with our clients’ websites**, including support for Shadow DOM and iFrames.
* **Optimized performance for faster loading and smoother execution of modifications**, enhancing the experience for visitors on our clients’ sites.

### **Enhanced Compatibility with Modern Technologies** <a href="#h_01jmcx5cbbctq28qzedzr8jdeh" id="h_01jmcx5cbbctq28qzedzr8jdeh"></a>

Our clients are developing increasingly complex websites, utilizing technologies like Shadow DOM and iFrames to structure their web applications. Previously, these implementations could pose compatibility challenges for our visual editor.&#x20;

### **Significant Performance Improvements** <a href="#h_01jmcx5cbb7tnbmw2kbsfn3fwe" id="h_01jmcx5cbb7tnbmw2kbsfn3fwe"></a>

Our teams have worked extensively to optimize the loading and execution times of the Modification Engine, leading to tangible improvements in overall site performance.

#### **Reduced Impact on Website Performance** <a href="#h_01jmcx5cbbcwmzkccbnp7fk6ch" id="h_01jmcx5cbbcwmzkccbnp7fk6ch"></a>

* **A lighter JavaScript tag**: The overall impact of AB Tasty has already been reduced by **2.3 KB**, with further optimizations planned.
* **Less impact on overall performance**: We observed an **improvement up to 11% in website performance**, depending on the number of modifications applied.

#### **Optimized Loading and Execution Times** <a href="#h_01jmcx5cbb12ff09ewptn5qjdx" id="h_01jmcx5cbb12ff09ewptn5qjdx"></a>

* **More efficient JavaScript execution**: The average execution time for modifications is **30% to 55% faster**.
* **Decreased "Render Blocking Time"**: Improvements range from **11% to 50%**, with even greater benefits for larger campaigns.
* **No longer classified as a “Long main-thread task”**

#### **Faster Application and Reapplication of Modifications** <a href="#h_01jmcx5cbbs7mxg8j0ync60a5y" id="h_01jmcx5cbbs7mxg8j0ync60a5y"></a>

Another key improvement in this update is the speed of applying and reapplying modifications:

* **Applying modifications is 2.2 to 2.75 times faster**.
* **Reapplying modifications is 4 to 5.7 times faster**, a major advantage for dynamic A/B testing.

### **Real-World Examples** <a href="#h_01jmcx5cbbfknywzb94g01g2vj" id="h_01jmcx5cbbfknywzb94g01g2vj"></a>

We conducted tests on various campaigns to measure these improvements in action:

#### **Campaign with 19 Modifications:** <a href="#h_01jmcx5cbb5sftbptm249z5e45" id="h_01jmcx5cbb5sftbptm249z5e45"></a>

* Total execution time: **1.79ms** (down from 3.96ms, **2.2 times faster**).
* Reapply time after a modification is removed: **0.58ms** (down from 3.34ms, **5.7 times faster**).
* **up to 5% improvement in overall site performance**.

#### **Campaign with 64 Modifications:** <a href="#h_01jmcx5cbcexfack08bevnz0yk" id="h_01jmcx5cbcexfack08bevnz0yk"></a>

* Total application time: **4ms** (down from 10-11ms, **2.5 to 2.75 times faster**).
* Reapply time after a modification is removed: **2.7ms** (down from 11-12ms, **4 to 4.4 times faster**).
* **Up to 11% improvement in overall site performance**.

### **Conclusion** <a href="#h_01jmcx5cbcy49pjhyekts94fqv" id="h_01jmcx5cbcy49pjhyekts94fqv"></a>

With these enhancements, our newest Modification Engine version is now more robust, faster, and better suited for modern websites. Our clients benefit from a smoother experience, and their visitors enjoy faster loading times without compromising user experience.

And this is just the beginning: our team continues to work on further optimizations to make our solution even more powerful in the coming months.

Feel free to test these improvements and share your feedback with us!


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