Here are a few key considerations when deciding whether to add subtitles in-app using native platform features or before uploading short-form social media videos:

Adding Before Upload:
Allows more control, customization, and ability to ensure accuracy of captions
But it is more time-consuming and requires additional tools and skills to create captions
It works for all platforms that don't have native caption support

Adding In-App:
Typically, it is very fast and easy to auto-generate captions
Accuracy can be hit or miss, depending on video content
Limited control and formatting options
Only works if platform has captioning capabilities built-in