If you're an influencer who wants a captioning tool that can handle vertical video and high-resolution video, AutoCaption is a strong contender. The AI-powered tool produces captions in Full HD at 60 frames per second, good for short-form videos and for social media like Instagram and TikTok. It can generate captions with a single click, edit subtitles with a lot of control and customize them with different styles, and handle vertical videos, so it should meet your needs.
Another option is RenderFit, which automatically creates attention-grabbing captions for videos to try to get people to watch. It can handle high-resolution video up to 1080x1920 or 1920x1080 and multiple languages. With features like emoji support, full styling control and real-time previews, it's a more advanced tool for creating captions.
If you want a tool that can caption videos and also convert text into a video, check out Typeframes. It offers customizable AI video templates, high-quality video exports and support for vertical video. It's geared for social-first creation, but it can help you create videos with a minimum of fuss, so it's a good option for influencers.