GitHub is the go-to platform for developers looking to version control their software, since it offers a command-line based interface, a web interface, and a desktop app too. This makes it an enticing option for developers who prefer using GUIs rather than remembering complex CLI commands. However, many customers are now complaining that GitHub has become painfully slow for them on select configurations.
According to multiple threads open on GitHub and Hacker News forums, GitHub has become severely slow on the default Apple Safari browser installed on Macs. According to the original poster on GitHub, when they try to open a pull request (PR) with more than a thousand lines of code or over a thousand lines of code changes, the browser takes a long time to render the code.
This peaks to the point that the browser displays blank spaces as you are scrolling up and down, the Activity Monitor shows the relevant rendering process at 100% utilization, and even search functionality doesn"t work correctly. According to the report, even switching between different views takes several seconds.
The original poster has been experiencing this behavior for the past few months on a fairly beefy Mac configuration, which is the 16-inch MacBook Pro with a 16-core Apple M4 Max and 48GB of RAM. They also claim that GitHub works completely fine in Chrome on the same Mac.
Others on the GitHub thread have echoed the same sentiments, with former Distinguished Microsoft Engineer Miguel de Icaza highlighting that this page with roughly 3,000 lines of code takes around 10 seconds to load on the generally available version of Safari and 5 seconds to render on a preview version of Safari. That said, it seems like the problem is not reliably reproducible looking at the ongoing debates over on Hacker News forums.
In our own testing on a modest Windows laptop with a 10th-gen Intel i7 processor and 16GB of RAM, the same page loaded within a couple of seconds on Chrome and Microsoft Edge and was fairly smooth during page up and down operations too. Meanwhile, the similarly modest 13-inch Mac M1 PC from 2020 with 16GB of RAM took over 20 seconds to render and also showed lots of blank spaces for several seconds while loading on Safari, while working perfectly well on Chrome. Apple and GitHub are yet to officially comment on the matter.