App Store Optimization (ASO) is the work of getting your app found in App Store and Google Play search and recommendations, and getting people to download it from the store page. Apple says App Store ranking depends on how well your name, subtitle, keywords, and category match the query, plus user behavior such as downloads and ratings. Spread terms across the name, subtitle, and keyword field without repeating them; then improve the screenshots and ratings that show in search results; and change one thing at a time while measuring impressions and conversion in App Analytics and Play Console.
What ASO Is — and How It Differs from SEO
The idea is the same as SEO: match the words searchers use and look worth choosing. The differences are that you can only edit the store's fixed fields, and the stores say plainly that user behavior counts toward ranking.
| Aspect | SEO | ASO |
|---|---|---|
| Where people search | Search engines such as Google | Search, recommendations, and categories inside the App Store and Google Play |
| What you can edit | Everything on the page (body, headings, structured data) | Fixed fields only (name, subtitle, keywords, description, images), each with a character limit |
| What ranks | Page content plus off-site signals such as links | Apple names text relevance and user behavior (downloads, ratings, reviews) |
| Time to change | Immediately on publish; indexing depends on crawling | Name, subtitle, and keywords change with a new version through App Review. Only promotional text updates instantly |
| How to measure | Search Console impressions, clicks, positions | App Analytics in App Store Connect / acquisition reports in Play Console (impressions, page views, downloads) |
App Store Fields That Do and Don't Affect Search
Apple's App Store search page lists text relevance (title, subtitle, keywords, primary category) and user behavior (downloads, ratings, reviews) as what determines results. The description isn't in that list, and promotional text is explicitly said not to affect ranking.
| Field | Limit | Role and how to write it |
|---|---|---|
| App name | 30 characters | Indexed, and the strongest field. Brand plus what the app does |
| Subtitle | 30 characters | Indexed. A summary under the name — put main terms that don't fit in the name here |
| Keywords | 100 characters | Indexed, invisible to users. Don't repeat words from the name or subtitle |
| Primary category | — | Indexed; the secondary category is indexed too |
| Promotional text | 170 characters | Apple says it doesn't affect search ranking. Editable without review — use it for current news |
| Description | 4,000 characters | Not listed among App Store search signals. Used for web search results after release |
| Screenshots | — | Up to three (or a preview) appear in search results and decide whether people tap |
A note on the keyword limit: Apple's guide says "100 characters, comma-separated," while App Store Connect Help says "100 bytes." In the seven apps we publish on the App Store, Japanese keyword fields of 40–75 characters (94–187 bytes in UTF-8) are live (checked November 11, 2026), so the field isn't cut at 100 bytes. Count it as 100 characters, and confirm with the remaining count in the field. Separate terms with commas and no spaces after them.
Google Play Fields and How to Write Them
Google Play has no dedicated keyword field. Instead, you write the name and descriptions as natural sentences; Play Console Help says repeated or unrelated keywords in the name or descriptions can get an app suspended.
| Field | Limit | Role and how to write it |
|---|---|---|
| App name | 30 characters | Say accurately what the app is. No promotional words like "free" or "No.1", no emoji |
| Short description | 80 characters | Read first on the details page — the main benefit in one sentence |
| Full description | 4,000 characters | Many read only the first lines. Don't repeat the short description. Keyword lists are prohibited |
| Keyword field | None | Google Play has no keyword field like the App Store's. Write the name and descriptions in natural sentences |
The Japanese version of the help page mentions both a half-count for full-width characters and a note that the limits apply regardless of character type. The character counter in Play Console is the reliable check.
How to Choose Keywords, Step by Step
- List the words people looking for this kind of app would type — by feature, problem solved, and situation
- Put the most important one or two terms in the app name and the next ones in the subtitle (30 characters each)
- Put the rest in the keyword field, minus words in the name, subtitle, or category, plurals, and overly broad words like "app"
- Check for competitor names, trademarks, and unrelated terms (grounds for rejection)
- After launch, watch search impressions and downloads in App Analytics and swap terms that don't work — one change per version
| When in doubt | Call |
|---|---|
| Newly launched, few ratings | Prefer terms that describe features specifically over broad ones like "work" or "game." Apple notes common terms are more competitive, especially for new apps and small businesses |
| Words already in the name or subtitle | Leave them out of the keyword field — duplicates waste space |
| Plurals, "app," "game," filler words | Leave them out; Apple lists them as things to avoid |
| Competitor app names, trademarks, celebrity names | Never. Grounds for rejection (Apple) or removal (Google Play) |
| Seasonal or trending terms | Can bring traffic but also competition. If it's time-limited, use an in-app event instead of the keyword field |
Google Suggest and Keyword Planner help collect candidates, but their numbers are Google searches, not searches inside the stores. Use them to widen the list and decide by the store's own numbers after launch. For collecting suggestions, see how to use suggested keywords, and for reading volumes, how to check search volume.
Screenshots and Ratings: What Gets You Chosen
App Store search results show the rating and up to three screenshots (or an app preview). Showing up isn't enough if nobody taps — check whether the first three screenshots explain what the app does at a glance.
- Ratings and reviews also affect search ranking (Apple). The rating prompt (SKStoreReviewController) can appear up to three times in 365 days — show it after a task is completed, when users are likely satisfied and not interrupted
- You can reply to reviews in App Store Connect; the reviewer is notified and can update the review. Prioritize one-star reviews and reports of bugs in the current version
- You can reset the summary rating, but Apple warns fewer ratings can mean fewer downloads. Use it carefully, when releasing a version that fixes past problems
- On Google Play, images and text can't include ranking claims like "No.1" or "top app," or price promotions like "% off"
When to Use In-App Events
In-app events show time-limited events as cards on the App Store (iOS and iPadOS 15+). People who have downloaded the app see the event card in search results, and events can be searched by name. They let seasonal or new content be found without rewriting your keyword field.
- Good fits: challenges, competitions, new modes or major updates, premieres
- Poor fits: recurring activities such as daily rewards, price promotions without new content, general promotion of the app
- Fields: event name (30 characters), short description (50), long description (120). No unverifiable superlatives or specific prices
- Events can run up to 31 days and be promoted up to 14 days before they start; up to 10 can be live on the App Store per app
Measuring and A/B Testing
Just as SEO relies on Search Console, ASO relies on the stores' consoles. App Analytics in App Store Connect shows impressions, conversion rate, and downloads, filterable by source type such as App Store search.
| Test | What you can test | Rules |
|---|---|---|
| App Store: Product page optimization | Icon, screenshots, app previews | Up to three treatments besides the original, up to 90 days. New assets need App Review. Apple recommends waiting until a treatment reaches 90% confidence |
| Google Play: Store listing experiments | Icon, feature graphic, screenshots, descriptions (localized tests) | One default graphics test or up to five localized tests at a time; up to two variants. Stops automatically after six months. Test one change at a time |
Neither test covers keyword ranking itself. For the name, subtitle, and keywords, log each version's release date and compare search impressions and downloads over equal periods before and after. With few downloads, tests take long to reach a result, so first check whether you're appearing in search at all (impressions).
On the App Store you can also assign keywords to custom product pages so a different page appears for those searches. Apple asks you not to overlap keywords across pages.
Use SEO for the App's Web Page
Outside the stores, people also search Google for your app name or the problem it solves. The App Store description is used in web search results after release, but the page you fully control is your own site's app page. Set its title, meta description, OGP, and structured data, and link to the store so visitors from search can reach the store page.
Common Mistakes
- Stuffing search terms into promotional text. Apple says it doesn't affect ranking
- Filling the keyword field with words already in the name or subtitle, or with plurals
- Listing related terms at the end of a Google Play description — Google Play prohibits keyword lists
- Putting "No.1," "free," or "% off" in the name or screenshots; Google Play's policy doesn't allow it
- Changing the name, keywords, and screenshots in the same version — you can't tell which one worked
- Asking for a rating right at launch. Apple recommends a moment when users are likely satisfied, such as after finishing a task
Related Tools
Sources (checked November 11, 2026)
- Apple Developer — App Store search (ranking factors, choosing keywords, promotional text doesn't affect ranking)
- App Store Connect Help — App information (name and subtitle: 30 characters)
- App Store Connect Help — Platform version information (promotional text 170, description 4,000, keywords 100 bytes)
- Apple Developer — Ratings, reviews, and responses (rating prompt up to three times in 365 days)
- Apple Developer — In-app events (30-character names, up to 31 days)
- Apple Developer — Product page optimization (up to three treatments, up to 90 days)
- Play Console Help — Create and set up your app (name, short and full description limits)
- Play Console Help — Best practices for your store listing (no keyword lists, rankings, or prices)
- Play Console Help — Run A/B tests on your store listing
FAQ
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Written by
今井政和SEO Director / Frontend Developer
SEO Director with 20+ years of web industry experience. Creator of Direbase and the official WordPress plugin "ORECTIC SEO CHECK." Author of a book on web strategy inspired by Edo-era merchant principles.
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