CaptionKit

CaptionKit is an iPhone app from Appers Limited that creates subtitles for videos. A user selects a video and the app recognises the speech and produces captions, with support for over 100 languages. It is aimed at content creators and influencers who publish on Instagram and TikTok, and at anyone who wants captions on a video without typing them by hand.

Captioning takes a few steps: the user picks a video from the gallery, CaptionKit's own AI transcribes the audio into text, and the subtitles are placed on the video. The captions can then be edited. A preview mode shows how the finished video will look on Instagram and TikTok so that subtitles are not hidden behind each platform's interface elements before the video is exported.

CaptionKit ships with over 20 subtitle templates, and a user can design a style of their own and reuse it in later projects. A built-in editor changes font, colour, outline, background and shadow, and several subtitle animations are available. Subtitles can be translated into other languages for a wider audience. Background music can be added to a video, with a volume control to balance it against the original sound.

CaptionKit is free to download with in-app purchases, listed as Caption Editor for Video at $5.99 and Video Editor for captions at $9.99, $24.99 and $69.99. It requires iOS 16.4 or later and is designed for iPhone only; it also runs on a Mac with an Apple M1 chip and on Apple Vision. The interface is offered in English and 16 other languages. The developer may collect identifiers, usage data and diagnostics.

Use cases

• Captioning short videos for Instagram and TikTok
• Translating subtitles to reach viewers in other languages
• Adding a music track under a captioned video