Part of the bargain we struck when we switched from building server-rendered websites to client-rendered SPAs is that we suddenly had to take a lot more care with the resources on the user’s device. Don’t block the UI thread, don’t make the laptop’s fan spin, don’t drain the phone’s battery, etc. We traded better interactivity and “app-like” behavior for a new class of problems that don’t really exist in the server-rendered world.

One of these problems is memory leaks. A poorly-coded SPA can easily eat up megabytes or even gigabytes of memory, continuing to gobble up more and more resources, even as it’s sitting innocently in a background tab. At this point, the page might start to slow to a crawl, or the browser may just terminate the tab and you’ll see Chrome’s familiar “Aw, snap!” page.