Idea Details

Thanks for continuing to share your feedback about the performance of Lightning. Since our last update we’ve made significant progress towards further optimizing page load times, and have some updates to share about how we plan to improve performance even further.

The median time to load a Lightning page is currently 1.4 seconds. In many cases page load times in Lightning are as fast or faster than Classic. We understand, though, that many customers are still seeing unacceptable page load times.

There are many things you can do to optimize performance for your org. A good place to start is by reviewing this knowledge article, which describes the factors impacting performance, how you can measure it, and various optimization techniques.

While there are many performance factors under your control, there are others, like network speed and client/browser speed, that are harder to control. We’d like to highlight two significant initiatives we're investing in that will improve the performance of Lightning, both in cases of slow network conditions as well as slow client/browser speeds. 

Salesforce EDGE boosts network performance by terminating connections closer to where users are, and then sending network traffic to your instance over an optimized route. You can read a little about EDGE in this Salesforce Engineering blog post. We’ll be able to share more about EDGE in the coming months.

Because Lightning renders its UI on the client, it's more sensitive than Classic to the client’s CPU speed and the browser Javascript engine. So all other things being equal, a page will take longer to render with a slower CPU than with a faster CPU.  But what if Lightning were powered by a UI framework that was less sensitive to things like CPU and Javascript engine speed? Such a UI framework exists, and it’s called Lightning Web Components.

You may have heard of Lightning Web components (LWC) when it was first announced in December 2018, or when we open sourced it at TrailheaDX earlier this year. LWC is a modern, standards-based UI framework that’s blazing fast. LWC has been well received in our developer community, with many partners reporting significant performance improvements when they migrated from Lightning aura components.  In fact, we have a case study showcasing the performance improvements of an entire Lightning application migrated to LWC.  Internally, we’ve begun the process of migrating many of the core parts of the Lightning UI, especially those found on record pages, to LWC as well.

The results so far are promising. In select cases we see improvements exceeding 40% in our performance labs. In certain production scenarios we see gains upwards of 20%. This is just the beginning. We expect even greater gains for select scenarios with the Winter ’20 release, and broader gains, over even more scenarios, over the next year.

Bear with us on this journey. We’ve heard loud and clear that Lightning performance isn’t where it needs to be. We’re investing heavily to improve things going forward, but it won’t happen overnight. And please keep the comments coming.