Subtitleとは？

The subtitle is one of the most valuable pieces of ASO real estate on iOS. It appears in every search result alongside your app name, making it one of the first things users read. It is also indexed by Apple's search algorithm, meaning the keywords you include directly influence your rankings.

With only 30 characters available, every word must earn its place. The best subtitles accomplish two things simultaneously: they include a high-value keyword that is not already in your title, and they communicate a clear benefit to the user. For example, a meditation app titled "Calm" might use the subtitle "Sleep, Meditation & Relaxation" — this adds three valuable keywords while telling users exactly what the app offers.

Avoid wasting subtitle characters on generic phrases like "The Best App" or your company name. Do not repeat keywords that are already in your title — Apple's algorithm will not give you additional ranking credit for duplicates. Instead, use the subtitle to target your second-most-important keyword cluster. Review your subtitle with every update — as your keyword strategy evolves, your subtitle should evolve with it. On Google Play, the equivalent field is the short description, which allows up to 80 characters and follows similar optimization principles.