What is ASO? App Store Optimization explained

ASO stands for App Store Optimization: getting your listing found in store search, and getting the people who find it to install. On iOS your searchable text is 160 bytes across three fields. On Google Play it is 4,110 characters, because Play reads the description Apple does not list.

Most of it is text you write once and revise. The rest is creative, ratings, and the app itself. None of it is a launch task you tick off, because search results change, competitors revise their listings, and the stores keep adding new surfaces.

The fields, by store

Field	App Store	Google Play	Search relevance
App name / title	30 characters	30 characters	Both stores
Subtitle	30 characters	Not available	App Store
Short description	Not available	80 characters	Google Play
Keyword field	100 bytes	Not available	App Store, hidden from users
Description	4,000 characters	4,000 characters	Play uses it as a search signal. Apple does not list its description as a search field.
Promotional text	170 characters	Not available	Apple says it does not affect ranking
What's New	4,000 characters	500 characters	Neither

Apple names the app name, subtitle, keywords and primary category as its text relevance factors. Choosing your category is a search decision, not an admin one. Google says Play search considers metadata such as title, description and category alongside quality and user response signals. Limits above come from the App Store Connect field reference and Google Play store listing documentation.

One trap worth knowing before you localize. Apple counts the keyword field in bytes, but the name and subtitle in characters. In English that makes no difference. In Czech, Russian or Japanese it does, because accented and non-Latin characters cost two or three bytes each. A Czech keyword field holds far less than 100 visible characters.

That gap is why pasting one listing into both consoles wastes space. Play can use your full description to understand the app. Apple does not list the description among its search fields, so the iOS version of that text has a different job: explain the product and convert the visitor.

ASO vs SEO

The instinct carries over. Understand what people search for, make the result relevant, improve what happens after they see it. The mechanics do not.

You have one product page per app instead of an open-ended set of pages, so the SEO reflex of shipping more pages has nowhere to go. You work to a byte budget rather than a word count. And there is no Search Console for the App Store, so you change metadata, ship a version, and wait, usually without knowing which change did it.

The bigger difference is that ranking and conversion are the same lever. Apple names downloads, ratings and reviews among its search factors. Google combines query relevance with app quality and how users respond to results. A listing that ranks well and converts badly does not keep the ranking for long.

Two newer App Store surfaces

Most ASO guides online predate both of these.

App Tags. Apple generates tags from your App Store Connect metadata, AI and human curation, and you deselect the ones that do not fit. They appear in search results, on search landing pages, and on your product page as tappable entities. Apple documents one hard limit: "Currently, tags are only supported and displayed to users across the App Store in the United States." Treat it as a US discovery surface, not a replacement for keywords. See managing App Tags.

Keywords on custom product pages. An approved custom product page can carry its own keywords, drawn from your latest approved version, and Apple can serve that page instead of your default one for matching searches. Keyword assignments are managed separately from an app update, but the page has to be approved, visible and published before it is searchable. See Apple's custom product page instructions.

Together they mean the 100 byte keyword field is no longer your entire keyword budget.

What actually moves it

Three parts, and the stores treat them separately.

Relevance comes from metadata: name, subtitle or short description, keyword field, description where it counts, category, and localization. This decides which searches you appear in and almost nothing else does.

Conversion comes from the icon, the first two screenshots, the rating, and whether the promise on the page matches the search that brought someone there. These are seen at thumbnail size, in a scrolling list, next to competitors, for about a second.

Quality continues after the install. Google explicitly counts technical performance and user experience in how it evaluates apps. Apple names user behavior, downloads, ratings and reviews.

No single field earns a rank. The job is to improve each part without changing five things at once and losing the ability to tell what worked.

Five ways this goes wrong

The keyword field is full of words you already rank for. Apple uses your name, subtitle and category for relevance. Repeating those words in the 100 byte field spends budget on terms you already own. Comma separated, no spaces after the commas, because a space is a byte.

One listing, pasted into both stores. The two stores expose different fields and describe their ranking differently. Write from one positioning brief and adapt the metadata per store.

Screenshots approved at full size. They get signed off on a 27 inch monitor and then compete as thumbnails. Check your first two frames at thumbnail scale, beside the apps that actually rank for your target query.

Metadata frozen at launch. Competitors rewrite their subtitles, search terms shift, the category gets more crowded every quarter. A listing you set once in March is quietly losing ground by September, and nothing in either console will tell you.

Ratings treated as support data. They shape trust on the product page, and both stores describe user feedback as a discovery or quality signal. An unanswered one star thread is the first thing a hesitant installer reads.

An ASO checklist for this week

Most app store optimization best practices you will find online are written for teams with an ASO manager. These ten are not, and none of them needs a tool you do not already have.

1. Search your three main terms in each store and capture the first five relevant results. That is your real competition, not the apps you think you compete with.
2. Write down every word already used in your app name and iOS subtitle. Those are done.
3. Rewrite the iOS keyword field using only words not on that list. Comma separated, no spaces, singular forms.
4. Check the subtitle says what the app does, not how it feels. It is indexed and it is read.
5. On Play, make the short description an accurate summary in 80 characters. It is indexed.
6. Rewrite the Play description for people and for search, without stuffing repeated terms.
7. View your icon at search-result size. If you cannot tell what it is, fix that before anything else.
8. Compare your first two screenshots as thumbnails against those actual search results.
9. Read the last 30 days of reviews for repeated objections and language gaps, and reply to the one star ones.
10. Record the date and the exact fields you changed, so the next review has a baseline.

Steps 1 to 6 fit in an afternoon. Steps 7 and 8 need a designer or a generator. Step 9 is the one everyone skips.

Change one cluster at a time. Update related metadata together, but do not replace the title, icon, screenshots and positioning in one untracked sweep. You need a clean record of what changed before you can learn anything from the result.

How often to revisit it

Monthly is a reasonable starting cadence for a small team. Sooner when a competitor moves, when a new term shows up in your reviews, or when a store adds a surface like App Tags.

Creative needs more planning, because the App Store splits your fields into two groups. Promotional text can be edited without a new version. Custom product page metadata can be submitted for review on its own. Approved screenshots cannot: Apple requires a new version before you can replace them. Batch the version-bound work with a release and run your smaller experiments in the fields that update on their own.

What it costs to skip

Nothing dramatic in any single week. That is the problem with it.

An app sitting on page two for its own category term gets found by people who already know its name. Installs come from wherever you push them from, and the store contributes close to nothing. Most solo developers read that as proof the store does not work for their kind of app and stop looking at it, which is what makes it true.

The apps that do get store traffic are rarely doing anything clever. They rewrote the subtitle twice, replaced the icon once, answered their reviews, and kept doing it.

What Uprate does with it

Uprate runs that cadence for you. Listing copy drafted from the build you actually ship, a pricing check across all 178 markets, reviews answered in your voice in 29 languages, and the icon and store set arriving as a draft.

The monthly review still happens. It just stops happening on your Sunday.

Nothing goes live until you approve it.