Will the tabs slow down my site?
No, the tabs will not slow down your site.
We've taken great care to make sure that the code for the tabs is highly efficient and extremely small (2 KB). It's also fully asynchronous, meaning it doesn't make the rest of the page wait while it's being loaded and run.
If the tabs code were to load slowly, the tabs would take longer to appear, but that's all. The rest of the page would not be affected in any way.
Instead of loading tabs immediately, you can load tabs after the page loads.