No, Core Web Vitals data is not real-time. It's based on the Chrome User Experience (CrUX) Report, which collects data from real user interactions with websites. This data typically has a delay of about a day or two.
While the data itself is only slightly delayed (typically 1-2 days), the rolling nature of the calculation means that improvements to your site may take some time to impact the final scores. As a result, you won't see immediate large changes in your Core Web Vitals metrics after making improvements. Instead, it may take several weeks for your enhancements to fully "tip the scale" and be reflected in the reported scores.