Definition
The Subtitle is a 30-character metadata field available exclusively on the Apple App Store, displayed directly below the App Title in search results and on the product page. It's the second-highest weighted indexed field for search ranking on iOS (after the title) and serves the dual purpose of keyword inclusion and value proposition communication.
The Subtitle has no equivalent on Google Play (which uses Short Description instead) or Amazon Appstore.
How It Works
Indexing mechanics:
- Indexed with the second-highest weight (after title)
- Words combine with App Title and Keyword Field words through Apple's combinatorial matching
- Example: "step" in title + "counter" in subtitle = automatically indexed for "step counter"
Display behavior:
- Shown in search results below the app name (smaller, lighter font)
- Shown on the product page below the title
- Full 30 characters typically visible
- Appears before screenshots in search result cards
Critical optimization rule: Do NOT repeat words already in the title. Apple indexes title + subtitle + keyword field as a combined set — duplicating wastes characters.
2024 edge case: Research shows the last word in a full 30-character subtitle may sometimes not index properly, nor create the phrase combinations it would normally build. If a keyword is critical, place it earlier in the subtitle or include it in the Keyword Field as backup.
Platform Comparison Context
| Platform | Equivalent Field | Limit | Indexed? |
|---|---|---|---|
| Apple | Subtitle | 30 chars | Yes (high weight) |
| Google Play | [[Short Description]] | 80 chars | Yes (medium weight) |
| Amazon | No equivalent | N/A | N/A |
Formulas & Metrics
Subtitle efficiency:
Efficiency = Unique_Non_Title_Keywords / Total_Words × 100%Target: 100% — every word should be a keyword not present in the title.
Character utilization:
Utilization = Characters_Used / 30 × 100%Target: >90%.
Best Practices
- Use all 30 characters — every unused character is wasted keyword opportunity.
- Zero overlap with title — if title is "PhotoApp - Photo Editor," don't put "photo" in subtitle. Use "Filters, Collage & Retouch" instead.
- Lead with keywords, end with benefit — "Task Planner & Daily Organizer" (keywords first) converts better than "Organize Your Day with Tasks" (benefit first, keyword last).
- Test with A/B tools — subtitle is not testable via Product Page Optimization (PPO). Use third-party tools (SplitMetrics, StoreMaven) to test subtitle variants.
- Update subtitle with each version — refresh keywords based on latest Keyword Research data. Subtitle changes require app submission.
- Place critical keywords early — due to the edge case where the final word in a full subtitle may not index, front-load your most important keywords.
Examples
App: Meditation app
- Title: "Calm Mind - Meditation" (21 chars)
- Bad subtitle: "Meditation & Calm Sessions" (repeats "meditation" and "calm" from title)
- Good subtitle: "Sleep, Breathing & Focus" (24 chars, 3 new keyword clusters)
App: Fitness tracker
- Title: "FitTrack: Workout Log" (21 chars)
- Good subtitle: "Gym Planner & Exercise Timer" (28 chars, 3 new keywords)
Dependencies
Influences (this term affects)
- Relevance Score — subtitle keywords contribute to relevance scoring
- Search Result Ranking — subtitle has second-highest ranking weight on iOS
- Keyword Indexing (iOS) — subtitle words enter combinatorial index
- Conversion Rate — subtitle communicates value proposition in search results
Depends On (affected by)
- App Title — subtitle must complement (not duplicate) title keywords
- Keyword Research — research determines optimal subtitle keywords
- Keyword Field — all three fields form the combined keyword set
- Apple Search Algorithm — algorithm determines subtitle's ranking weight
Related Terms
Sources & Further Reading
- Gummicube: App Store Subtitle Optimization
- ASOMobile: Text Optimization for App Store
- Stormy AI: iOS Keywords Playbook (2025)