Why isn't my video displaying in 4K on YouTube? (iOS)

If you find that your video is not viewable in 4K after uploading to YouTube, it's likely still processing. This is because high quality videos need extra time to fully process, which is why you'll initially see the upload at a lower resolution. Processing times can vary and depend on certain factors, like format, length, and resolution. It's also advisable to check whether your internet browser supports higher resolution playback, as this can also vary.

For additional information, please refer to the following YouTube support page: Low video quality after upload